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[PMID]:28531287
[Au] Autor:Julius C; Yuzenkova Y
[Ad] Endereço:Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Baddiley-Clark Building, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK.
[Ti] Título:Bacterial RNA polymerase caps RNA with various cofactors and cell wall precursors.
[So] Source:Nucleic Acids Res;45(14):8282-8290, 2017 Aug 21.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Bacterial RNA polymerase is able to initiate transcription with adenosine-containing cofactor NAD+, which was proposed to result in a portion of cellular RNAs being 'capped' at the 5' end with NAD+, reminiscent of eukaryotic cap. Here we show that, apart from NAD+, another adenosine-containing cofactor FAD and highly abundant uridine-containing cell wall precursors, UDP-Glucose and UDP-N-acetylglucosamine are efficiently used to initiate transcription in vitro. We show that the affinity to NAD+ and UDP-containing factors during initiation is much lower than their cellular concentrations, and that initiation with them stimulates promoter escape. Efficiency of initiation with NAD+, but not with UDP-containing factors, is affected by amino acids of the Rifampicin-binding pocket, suggesting altered RNA capping in Rifampicin-resistant strains. However, relative affinity to NAD+ does not depend on the -1 base of the template strand, as was suggested earlier. We show that incorporation of mature cell wall precursor, UDP-MurNAc-pentapeptide, is inhibited by region 3.2 of σ subunit, possibly preventing targeting of RNA to the membrane. Overall, our in vitro results propose a wide repertoire of potential bacterial RNA capping molecules, and provide mechanistic insights into their incorporation.
[Mh] Termos MeSH primário: Proteínas de Bactérias/genética
Parede Celular/genética
RNA Polimerases Dirigidas por DNA/genética
Capuzes de RNA/genética
Transcrição Genética
[Mh] Termos MeSH secundário: Proteínas de Bactérias/metabolismo
Sequência de Bases
Parede Celular/metabolismo
RNA Polimerases Dirigidas por DNA/metabolismo
Flavina-Adenina Dinucleotídeo/metabolismo
NAD/metabolismo
Capuzes de RNA/metabolismo
Homologia de Sequência do Ácido Nucleico
Uridina Difosfato Glucose/metabolismo
Uridina Difosfato N-Acetilglicosamina/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (RNA Caps); 0U46U6E8UK (NAD); 146-14-5 (Flavin-Adenine Dinucleotide); 528-04-1 (Uridine Diphosphate N-Acetylglucosamine); EC 2.7.7.6 (DNA-Directed RNA Polymerases); V50K1D7P4Y (Uridine Diphosphate Glucose)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171023
[Lr] Data última revisão:
171023
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170523
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkx452


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[PMID]:27545601
[Au] Autor:Joo SH; Chung HS
[Ad] Endereço:Department of Pharmacy, Catholic University of Daegu, Gyeongbuk 38430, South Korea; Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
[Ti] Título:Crystal structure and activity of Francisella novicida UDP-N-acetylglucosamine acyltransferase.
[So] Source:Biochem Biophys Res Commun;478(3):1223-9, 2016 09 23.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The first step of lipid A biosynthesis in Escherichia coli (E. coli) is catalyzed by LpxA (EcLpxA), an acyltransferase selective for UDP-N-acetylglucosamine (UDP-GlcNAc) and R-3-hydroxymyristoyl-acyl carrier protein (3-OH-C14-ACP), and is an essential step in majority of Gram-negative bacteria. Since the majority of lipid A species isolated from F. novicida contains 3-OH-C16 or 3-OH-C18 at its C3 and C3' positions, FnLpxA was thought to be selective for longer acyl chain (3-OH-C16 and 3-OH-C18) over short acyl chain (3-OH-C14, 3-OH-C12, and 3-OH-C10). Here we demonstrate that Francisella novicida (F. novicida) lpxA functionally complements an E. coli lpxA knockout mutant and efficiently transfers 3-OH-C14 as well as 3-OH-C16 in E. coli. Our results implicate that the acyl chain length of lipid A is determined by several factors including acyl chain selectivity of LpxA and downstream enzymes, as well as the composition of the acyl-ACP pool in vivo. We also report the crystal structure of F. novicida LpxA (FnLpxA) at 2.06 Å. The N-terminal parallel beta-helix (LßH) and C-terminal alpha-helical domain are similar to other reported structures of LpxAs. However, our structure indicates that the supposed ruler residues for hydrocarbon length, 171L in one monomer and 168H in the adjacent monomer in a functional trimer of FnLpxA, are located just 3.8 Å apart that renders not enough space for binding of 3-OH-C12 or longer acyl chains. This implicates that FnLpxA may have an alternative hydrophobic pocket, or the acyl chain may bend while binding to FnLpxA. In addition, the FnLpxA structure suggests a potential inhibitor binding site for development of antibiotics.
[Mh] Termos MeSH primário: Aciltransferases/química
Proteínas de Bactérias/química
Francisella/enzimologia
Uridina Difosfato N-Acetilglicosamina/química
[Mh] Termos MeSH secundário: Aciltransferases/antagonistas & inibidores
Aciltransferases/metabolismo
Proteínas de Bactérias/metabolismo
Sítios de Ligação
Cristalografia por Raios X
Inibidores Enzimáticos/química
Inibidores Enzimáticos/farmacologia
Escherichia coli/metabolismo
Técnicas de Inativação de Genes
Lipídeo A/química
Modelos Moleculares
Uridina Difosfato N-Acetilglicosamina/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Enzyme Inhibitors); 0 (Lipid A); 528-04-1 (Uridine Diphosphate N-Acetylglucosamine); EC 2.3.- (Acyltransferases)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:171127
[Lr] Data última revisão:
171127
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160823
[St] Status:MEDLINE


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[PMID]:27111141
[Au] Autor:Swamy M; Pathak S; Grzes KM; Damerow S; Sinclair LV; van Aalten DM; Cantrell DA
[Ad] Endereço:Division of Cell Signalling and Immunology, University of Dundee, Dundee, UK.
[Ti] Título:Glucose and glutamine fuel protein O-GlcNAcylation to control T cell self-renewal and malignancy.
[So] Source:Nat Immunol;17(6):712-20, 2016 06.
[Is] ISSN:1529-2916
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Sustained glucose and glutamine transport are essential for activated T lymphocytes to support ATP and macromolecule biosynthesis. We found that glutamine and glucose also fuel an indispensable dynamic regulation of intracellular protein O-GlcNAcylation at key stages of T cell development, transformation and differentiation. Glucose and glutamine are precursors of uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), a substrate for cellular glycosyltransferases. Immune-activated T cells contained higher concentrations of UDP-GlcNAc and increased intracellular protein O-GlcNAcylation controlled by the enzyme O-linked-ß-N-acetylglucosamine (O-GlcNAc) glycosyltransferase as compared with naive cells. We identified Notch, the T cell antigen receptor and c-Myc as key controllers of T cell protein O-GlcNAcylation via regulation of glucose and glutamine transport. Loss of O-GlcNAc transferase blocked T cell progenitor renewal, malignant transformation and peripheral T cell clonal expansion. Nutrient-dependent signaling pathways regulated by O-GlcNAc glycosyltransferase are thus fundamental for T cell biology.
[Mh] Termos MeSH primário: Glucose/metabolismo
Glutamina/metabolismo
N-Acetilglucosaminiltransferases/metabolismo
Proteínas Proto-Oncogênicas c-myc/metabolismo
Receptores de Antígenos de Linfócitos T/metabolismo
Linfócitos T/fisiologia
Uridina Difosfato N-Acetilglicosamina/metabolismo
[Mh] Termos MeSH secundário: Animais
Proliferação Celular/genética
Autorrenovação Celular/genética
Transformação Celular Neoplásica/genética
Células Clonais
Feminino
Ativação Linfocitária/genética
Proteína Tirosina Quinase p56(lck) Linfócito-Específica/genética
Masculino
Camundongos
Camundongos Endogâmicos C57BL
Camundongos Knockout
N-Acetilglucosaminiltransferases/genética
Proteínas Proto-Oncogênicas c-myc/genética
Receptores Notch/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Myc protein, mouse); 0 (Proto-Oncogene Proteins c-myc); 0 (Receptors, Antigen, T-Cell); 0 (Receptors, Notch); 0RH81L854J (Glutamine); 528-04-1 (Uridine Diphosphate N-Acetylglucosamine); EC 2.4.1.- (N-Acetylglucosaminyltransferases); EC 2.7.10.2 (Lymphocyte Specific Protein Tyrosine Kinase p56(lck)); IY9XDZ35W2 (Glucose)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:171101
[Lr] Data última revisão:
171101
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160426
[St] Status:MEDLINE
[do] DOI:10.1038/ni.3439


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[PMID]:26883802
[Au] Autor:Deen AJ; Arasu UT; Pasonen-Seppänen S; Hassinen A; Takabe P; Wojciechowski S; Kärnä R; Rilla K; Kellokumpu S; Tammi R; Tammi M; Oikari S
[Ad] Endereço:Institute of Biomedicine, School of Medicine, University of Eastern Finland, 70210, Kuopio, Finland. ashik.jawahardeen@uef.fi.
[Ti] Título:UDP-sugar substrates of HAS3 regulate its O-GlcNAcylation, intracellular traffic, extracellular shedding and correlate with melanoma progression.
[So] Source:Cell Mol Life Sci;73(16):3183-204, 2016 Aug.
[Is] ISSN:1420-9071
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:Hyaluronan content is a powerful prognostic factor in many cancer types, but the molecular basis of its synthesis in cancer still remains unclear. Hyaluronan synthesis requires the transport of hyaluronan synthases (HAS1-3) from Golgi to plasma membrane (PM), where the enzymes are activated. For the very first time, the present study demonstrated a rapid recycling of HAS3 between PM and endosomes, controlled by the cytosolic levels of the HAS substrates UDP-GlcUA and UDP-GlcNAc. Depletion of UDP-GlcNAc or UDP-GlcUA shifted the balance towards HAS3 endocytosis, and inhibition of hyaluronan synthesis. In contrast, UDP-GlcNAc surplus suppressed endocytosis and lysosomal decay of HAS3, favoring its retention in PM, stimulating hyaluronan synthesis, and HAS3 shedding in extracellular vesicles. The concentration of UDP-GlcNAc also controlled the level of O-GlcNAc modification of HAS3. Increasing O-GlcNAcylation reproduced the effects of UDP-GlcNAc surplus on HAS3 trafficking, while its suppression showed the opposite effects, indicating that O-GlcNAc signaling is associated to UDP-GlcNAc supply. Importantly, a similar correlation existed between the expression of GFAT1 (the rate limiting enzyme in UDP-GlcNAc synthesis) and hyaluronan content in early and deep human melanomas, suggesting the association of UDP-sugar metabolism in initiation of melanomagenesis. In general, changes in glucose metabolism, realized through UDP-sugar contents and O-GlcNAc signaling, are important in HAS3 trafficking, hyaluronan synthesis, and correlates with melanoma progression.
[Mh] Termos MeSH primário: Glucuronosiltransferase/metabolismo
Ácido Hialurônico/metabolismo
Melanoma/metabolismo
Neoplasias Cutâneas/metabolismo
Pele/metabolismo
Açúcares de Uridina Difosfato/metabolismo
[Mh] Termos MeSH secundário: Acetilglucosamina/metabolismo
Acilação
Animais
Células COS
Linhagem Celular
Linhagem Celular Tumoral
Cercopithecus aethiops
Progressão da Doença
Endocitose
Seres Humanos
Hialuronan Sintases
Melanoma/patologia
Transporte Proteico
Pele/patologia
Neoplasias Cutâneas/patologia
Uridina Difosfato N-Acetilglicosamina/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Uridine Diphosphate Sugars); 528-04-1 (Uridine Diphosphate N-Acetylglucosamine); 9004-61-9 (Hyaluronic Acid); EC 2.4.1.17 (Glucuronosyltransferase); EC 2.4.1.17 (HAS1 protein, human); EC 2.4.1.212 (HAS3 protein, human); EC 2.4.1.212 (Hyaluronan Synthases); V956696549 (Acetylglucosamine)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160218
[St] Status:MEDLINE
[do] DOI:10.1007/s00018-016-2158-5


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[PMID]:26598987
[Au] Autor:Zhang L; Muthana MM; Yu H; McArthur JB; Qu J; Chen X
[Ad] Endereço:Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA.
[Ti] Título:Characterizing non-hydrolyzing Neisseria meningitidis serogroup A UDP-N-acetylglucosamine (UDP-GlcNAc) 2-epimerase using UDP-N-acetylmannosamine (UDP-ManNAc) and derivatives.
[So] Source:Carbohydr Res;419:18-28, 2016 Jan.
[Is] ISSN:1873-426X
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Neisseria meningitidis serogroup A non-hydrolyzing uridine 5'-diphosphate-N-acetylglucosamine (UDP-GlcNAc) 2-epimerase (NmSacA) catalyzes the interconversion between UDP-GlcNAc and uridine 5'-diphosphate-N-acetylmannosamine (UDP-ManNAc). It is a key enzyme involved in the biosynthesis of the capsular polysaccharide [-6ManNAcα1-phosphate-]n of N. meningitidis serogroup A, one of the six serogroups (A, B, C, W-135, X, and Y) that account for most cases of N. meningitidis-caused bacterial septicemia and meningitis. N. meningitidis serogroup A is responsible for large epidemics in the developing world, especially in Africa. Here we report that UDP-ManNAc could be used as a substrate for C-terminal His6-tagged recombinant NmSacA (NmSacA-His6) in the absence of UDP-GlcNAc. NmSacA-His6 was activated by UDP-GlcNAc and inhibited by 2-acetamidoglucal and UDP. Substrate specificity study showed that NmSacA-His6 could tolerate several chemoenzymatically synthesized UDP-ManNAc derivatives as substrates although its activity was much lower than non-modified UDP-ManNAc. Homology modeling and molecular docking revealed likely structural determinants of NmSacA substrate specificity. This is the first detailed study of N. meningitidis serogroup A UDP-GlcNAc 2-epimerase.
[Mh] Termos MeSH primário: Neisseria meningitidis/enzimologia
Uridina Difosfato N-Acetilglicosamina/química
Uridina Difosfato N-Acetilglicosamina/metabolismo
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Carboidratos Epimerases/antagonistas & inibidores
Carboidratos Epimerases/química
Carboidratos Epimerases/genética
Carboidratos Epimerases/metabolismo
Domínio Catalítico
Clonagem Molecular
Ativação Enzimática/efeitos dos fármacos
Inibidores Enzimáticos/metabolismo
Inibidores Enzimáticos/farmacologia
Hexosaminas/metabolismo
Hexosaminas/farmacologia
Simulação de Acoplamento Molecular
Dados de Sequência Molecular
Neisseria meningitidis/genética
Especificidade por Substrato
Difosfato de Uridina/metabolismo
Difosfato de Uridina/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzyme Inhibitors); 0 (Hexosamines); 10293-59-1 (2-acetamidoglucal); 528-04-1 (Uridine Diphosphate N-Acetylglucosamine); 58-98-0 (Uridine Diphosphate); EC 5.1.3.- (Carbohydrate Epimerases); EC 5.1.3.14 (UDP acetylglucosamine-2-epimerase)
[Em] Mês de entrada:1610
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151125
[St] Status:MEDLINE


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[PMID]:26592348
[Au] Autor:Shi JF; Fu J; Mu LL; Guo WC; Li GQ
[Ad] Endereço:Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: shijf1214@126.com.
[Ti] Título:Two Leptinotarsa uridine diphosphate N-acetylglucosamine pyrophosphorylases are specialized for chitin synthesis in larval epidermal cuticle and midgut peritrophic matrix.
[So] Source:Insect Biochem Mol Biol;68:1-12, 2016 Jan.
[Is] ISSN:1879-0240
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Uridine diphosphate-N-acetylglucosamine-pyrophosphorylase (UAP) is involved in the biosynthesis of chitin, an essential component of the epidermal cuticle and midgut peritrophic matrix (PM) in insects. In the present paper, two putative LdUAP genes were cloned in Leptinotarsa decemlineata. In vivo bioassay revealed that 20-hydroxyecdysone (20E) and an ecdysteroid agonist halofenozide activated the expression of the two LdUAPs, whereas a decrease in 20E by RNA interference (RNAi) of an ecdysteroidogenesis gene LdSHD and a 20E signaling gene LdFTZ-F1 repressed the expression. Juvenile hormone (JH), a JH analog pyriproxyfen and an increase in JH by RNAi of an allatostatin gene LdAS-C downregulated LdUAP1 but upregulated LdUAP2, whereas a decrease in JH by silencing of a JH biosynthesis gene LdJHAMT had converse effects. Thus, expression of LdUAPs responded to both 20E and JH. Moreover, knockdown of LdUAP1 reduced chitin contents in whole larvae and integument samples, thinned tracheal taenidia, impaired larval-larval molt, larval-pupal ecdysis and adult emergence. In contrast, silencing of LdUAP2 significantly reduced foliage consumption, decreased chitin content in midgut samples, damaged PM, and retarded larval growth. The resulting larvae had lighter fresh weights, smaller body sizes and depleted fat body. As a result, the development was arrested. Combined knockdown of LdUAP1 and LdUAP2 caused an additive negative effect. Our data suggest that LdUAP1 and LdUAP2 have specialized functions in biosynthesizing chitin in the epidermal cuticle and PM respectively in L. decemlineata.
[Mh] Termos MeSH primário: Quitina/biossíntese
Coleópteros/metabolismo
Proteínas de Insetos/metabolismo
Uridina Difosfato N-Acetilglicosamina/metabolismo
[Mh] Termos MeSH secundário: Animais
Clonagem Molecular
Coleópteros/genética
Coleópteros/crescimento & desenvolvimento
Sistema Digestório/metabolismo
Ecdisterona/metabolismo
Genes de Insetos
Proteínas de Insetos/genética
Hormônios Juvenis/metabolismo
Larva/metabolismo
Muda/genética
Uridina Difosfato N-Acetilglicosamina/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Insect Proteins); 0 (Juvenile Hormones); 1398-61-4 (Chitin); 528-04-1 (Uridine Diphosphate N-Acetylglucosamine); 5289-74-7 (Ecdysterone)
[Em] Mês de entrada:1609
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151124
[St] Status:MEDLINE


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[PMID]:26499076
[Au] Autor:Lim K; Yoon BH; Ha CH
[Ad] Endereço:David H. Smith Center for Vaccine Biology and Immunology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 609, Rochester, NY 14642, United States.
[Ti] Título:O-Linked N-acetylglucosaminylation of Sp1 interferes with Sp1 activation of glycolytic genes.
[So] Source:Biochem Biophys Res Commun;468(1-2):349-53, 2015 Dec 4-11.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Glycolysis, the primary pathway metabolizing glucose for energy production, is connected to the hexosamine biosynthetic pathway (HBP) which produces UDP-N-acetylglucosamine (UDP-GlcNAc), a GlcNAc donor for O-linked GlcNAc modification (O-GlcNAc), as well as for traditional elongated glycosylation. Thus, glycolysis and O-GlcNAc are intimately associated. The present study reports the transcriptional activation of glycolytic genes by the transcription factor Sp1 and the O-GlcNAc-mediated suppression of Sp1-dependent activation of glycolytic genes. O-GlcNAc-deficient mutant Sp1 stimulated the transcription of nine glycolytic genes and cellular production of pyruvate, the final product of glycolysis, to a greater extent than wild-type Sp1. Consistently, this mutant Sp1 increased the protein levels of the two key glycolytic enzymes, phosphofructokinase (PFK) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH), to a greater extent than wild-type Sp1. Finally, the mutant Sp1 occupied GC-rich elements on PFK and GAPDH promoters more efficiently than wild-type Sp1. These results suggest that O-GlcNAcylation of Sp1 suppresses Sp1-mediated activation of glycolytic gene transcription.
[Mh] Termos MeSH primário: Glicólise
Fator de Transcrição Sp1/metabolismo
Ativação Transcricional
Uridina Difosfato N-Acetilglicosamina/metabolismo
[Mh] Termos MeSH secundário: Sequência de Bases
Gliceraldeído-3-Fosfato Desidrogenases/genética
Células HEK293
Seres Humanos
Dados de Sequência Molecular
Mutação
Fosfofrutoquinases/genética
Regiões Promotoras Genéticas
Fator de Transcrição Sp1/genética
Uridina Difosfato N-Acetilglicosamina/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Sp1 Transcription Factor); 528-04-1 (Uridine Diphosphate N-Acetylglucosamine); EC 1.2.1.- (Glyceraldehyde-3-Phosphate Dehydrogenases); EC 2.7.1 - (Phosphofructokinases)
[Em] Mês de entrada:1603
[Cu] Atualização por classe:151124
[Lr] Data última revisão:
151124
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151027
[St] Status:MEDLINE


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[PMID]:26352800
[Au] Autor:Smith EW; Zhang X; Behzadi C; Andrews LD; Cohen F; Chen Y
[Ad] Endereço:Department of Molecular Medicine, University of South Florida , 12901 Bruce B. Downs Boulevard, Tampa, Florida 33612, United States.
[Ti] Título:Structures of Pseudomonas aeruginosa LpxA Reveal the Basis for Its Substrate Selectivity.
[So] Source:Biochemistry;54(38):5937-48, 2015 Sep 29.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In Gram-negative bacteria, the first step of lipid A biosynthesis is catalyzed by UDP-N-acetylglucosamine acyltransferase (LpxA) through the transfer of a R-3-hydroxyacyl chain from the acyl carrier protein (ACP) to the 3-hydroxyl group of UDP-GlcNAc. Previous studies suggest that LpxA is a critical determinant of the acyl chain length found in lipid A, which varies among species of bacteria. In Escherichia coli and Leptospira interrogans, LpxA prefers to incorporate longer R-3-hydroxyacyl chains (C14 and C12, respectively), whereas in Pseudomonas aeruginosa, the enzyme is selective for R-3-hydroxydecanoyl, a 10-hydrocarbon long acyl chain. We now report three P. aeruginosa LpxA crystal structures: apo protein, substrate complex with UDP-GlcNAc, and product complex with UDP-3-O-(R-3-hydroxydecanoyl)-GlcNAc. A comparison between the apo form and complexes identifies key residues that position UDP-GlcNAc appropriately for catalysis and supports the role of catalytic His121 in activating the UDP-GlcNAc 3-hydroxyl group for nucleophilic attack during the reaction. The product-complex structure, for the first time, offers structural insights into how Met169 serves to constrain the length of the acyl chain and thus functions as the so-called hydrocarbon ruler. Furthermore, compared with ortholog LpxA structures, the purported oxyanion hole, formed by the backbone amide group of Gly139, displays a different conformation in P. aeruginosa LpxA, which suggests flexibility of this structural feature important for catalysis and the potential need for substrate-induced conformational change in catalysis. Taken together, the three structures provide valuable insights into P. aeruginosa LpxA catalysis and substrate specificity as well as templates for future inhibitor discovery.
[Mh] Termos MeSH primário: Aciltransferases/química
Pseudomonas aeruginosa/enzimologia
[Mh] Termos MeSH secundário: Aciltransferases/metabolismo
Sequência de Aminoácidos
Cristalografia por Raios X
Seres Humanos
Modelos Moleculares
Dados de Sequência Molecular
Conformação Proteica
Multimerização Proteica
Infecções por Pseudomonas/microbiologia
Pseudomonas aeruginosa/química
Pseudomonas aeruginosa/metabolismo
Especificidade por Substrato
Uridina Difosfato N-Acetilglicosamina/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
528-04-1 (Uridine Diphosphate N-Acetylglucosamine); EC 2.3.- (Acyltransferases); EC 2.3.1.129 (acyl-(acyl-carrier-protein)-UDP-N-acetylglucosamine acyltransferase)
[Em] Mês de entrada:1601
[Cu] Atualização por classe:150929
[Lr] Data última revisão:
150929
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150910
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.5b00720


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[PMID]:26306635
[Au] Autor:Engel J; Schmalhorst PS; Krüger AT; Müller CT; Buettner FF; Routier FH
[Ad] Endereço:Department of Cellular Chemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, Hannover 30625, Germany.
[Ti] Título:Characterization of an N-acetylglucosaminyltransferase involved in Aspergillus fumigatus zwitterionic glycoinositolphosphoceramide biosynthesis.
[So] Source:Glycobiology;25(12):1423-30, 2015 Dec.
[Is] ISSN:1460-2423
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Glycoinositolphosphoceramides (GIPCs) are complex sphingolipids present at the plasma membrane of various eukaryotes with the important exception of mammals. In fungi, these glycosphingolipids commonly contain an α-mannose residue (Man) linked at position 2 of the inositol. However, several pathogenic fungi additionally synthesize zwitterionic GIPCs carrying an α-glucosamine residue (GlcN) at this position. In the human pathogen Aspergillus fumigatus, the GlcNα1,2IPC core (where IPC is inositolphosphoceramide) is elongated to Manα1,3Manα1,6GlcNα1,2IPC, which is the most abundant GIPC synthesized by this fungus. In this study, we identified an A. fumigatus N-acetylglucosaminyltransferase, named GntA, and demonstrate its involvement in the initiation of zwitterionic GIPC biosynthesis. Targeted deletion of the gene encoding GntA in A. fumigatus resulted in complete absence of zwitterionic GIPC; a phenotype that could be reverted by episomal expression of GntA in the mutant. The N-acetylhexosaminyltransferase activity of GntA was substantiated by production of N-acetylhexosamine-IPC in the yeast Saccharomyces cerevisiae upon GntA expression. Using an in vitro assay, GntA was furthermore shown to use UDP-N-acetylglucosamine as donor substrate to generate a glycolipid product resistant to saponification and to digestion by phosphatidylinositol-phospholipase C as expected for GlcNAcα1,2IPC. Finally, as the enzymes involved in mannosylation of IPC, GntA was localized to the Golgi apparatus, the site of IPC synthesis.
[Mh] Termos MeSH primário: Aspergillus fumigatus/enzimologia
Ceramidas/metabolismo
Proteínas Fúngicas/metabolismo
N-Acetilglucosaminiltransferases/metabolismo
[Mh] Termos MeSH secundário: Aspergillus fumigatus/genética
Proteínas Fúngicas/genética
Deleção de Genes
Manose/metabolismo
N-Acetilglucosaminiltransferases/genética
Saccharomyces cerevisiae/genética
Saccharomyces cerevisiae/metabolismo
Uridina Difosfato N-Acetilglicosamina/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Ceramides); 0 (Fungal Proteins); 528-04-1 (Uridine Diphosphate N-Acetylglucosamine); EC 2.4.1.- (N-Acetylglucosaminyltransferases); PHA4727WTP (Mannose)
[Em] Mês de entrada:1608
[Cu] Atualização por classe:151106
[Lr] Data última revisão:
151106
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150827
[St] Status:MEDLINE
[do] DOI:10.1093/glycob/cwv059


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[PMID]:26207987
[Au] Autor:Hwang S; Aronov A; Bar-Peled M
[Ad] Endereço:Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, United States of America.
[Ti] Título:The Biosynthesis of UDP-D-QuiNAc in Bacillus cereus ATCC 14579.
[So] Source:PLoS One;10(7):e0133790, 2015.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:N-acetylquinovosamine (2-acetamido-2,6-di-deoxy-D-glucose, QuiNAc) is a relatively rare amino sugar residue found in glycans of few pathogenic gram-negative bacteria where it can play a role in infection. However, little is known about QuiNAc-related polysaccharides in gram-positive bacteria. In a routine screen for bacillus glycan grown at defined medium, it was surprising to identify a QuiNAc residue in polysaccharides isolated from this gram-positive bacterium. To gain insight into the biosynthesis of these glycans, we report the identification of an operon in Bacillus cereus ATCC 14579 that contains two genes encoding activities not previously described in gram-positive bacteria. One gene encodes a UDP-N-acetylglucosamine C4,6-dehydratase, (abbreviated Pdeg) that converts UDP-GlcNAc to UDP-4-keto-4,6-D-deoxy-GlcNAc (UDP-2-acetamido-2,6-dideoxy-α-D-xylo-4-hexulose); and the second encodes a UDP-4-reductase (abbr. Preq) that converts UDP-4-keto-4,6-D-deoxy-GlcNAc to UDP-N-acetyl-quinovosamine in the presence of NADPH. Biochemical studies established that the sequential Pdeg and Preq reaction product is UDP-D-QuiNAc as determined by mass spectrometry and one- and two-dimensional NMR experiments. Also, unambiguous evidence for the conversions of the dehydratase product, UDP-α-D-4-keto-4,6-deoxy-GlcNAc, to UDP-α-D-QuiNAc was obtained using real-time 1H-NMR spectroscopy and mass spectrometry. The two genes overlap by 4 nucleotides and similar operon organization and identical gene sequences were also identified in a few other Bacillus species suggesting they may have similar roles in the lifecycle of this class of bacteria important to human health. Our results provide new information about the ability of Bacilli to form UDP-QuiNAc and will provide insight to evaluate their role in the biology of Bacillus.
[Mh] Termos MeSH primário: Acetilglucosamina/análogos & derivados
Bacillus cereus/metabolismo
[Mh] Termos MeSH secundário: Acetilglucosamina/biossíntese
Proteínas de Bactérias/metabolismo
Oxirredutases/metabolismo
Uridina Difosfato N-Acetilglicosamina/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (2-acetamido-2,6-dideoxy-glucose (N-acetyl-quinovosamine)); 0 (Bacterial Proteins); 528-04-1 (Uridine Diphosphate N-Acetylglucosamine); EC 1.- (Oxidoreductases); V956696549 (Acetylglucosamine)
[Em] Mês de entrada:1605
[Cu] Atualização por classe:150731
[Lr] Data última revisão:
150731
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150725
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0133790



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