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[PMID]:29051067
[Au] Autor:Wang Y; Ryu BH; Yoo W; Lee CW; Kim KK; Lee JH; Kim TD
[Ad] Endereço:Department of Chemistry, College of Natural Science, Sookmyung Women's University, Seoul 04310, Republic of Korea.
[Ti] Título:Identification, characterization, immobilization, and mutational analysis of a novel acetylesterase with industrial potential (LaAcE) from Lactobacillus acidophilus.
[So] Source:Biochim Biophys Acta;1862(1):197-210, 2018 01.
[Is] ISSN:0006-3002
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Lactic acid bacteria, which are involved in the fermentation of vegetables, meats, and dairy products, are widely used for the productions of small organic molecules and bioactive peptides. Here, a novel acetylesterase (LaAcE) from Lactobacillus acidophilus NCFM was identified, functionally characterized, immobilized, and subjected to site-directed mutagenesis for biotechnological applications. The enzymatic properties of LaAcE were investigated using biochemical and biophysical methods including native polyacrylamide gel electrophoresis, acetic acid release, biochemical assays, enzyme kinetics, and spectroscopic methods. Interestingly, LaAcE exhibited the ability to act on a broad range of substrates including glucose pentaacetate, glyceryl tributyrate, fish oil, and fermentation-related compounds. Furthermore, immobilization of LaAcE showed good recycling ability and high thermal stability compared with free LaAcE. A structural model of LaAcE was used to guide mutational analysis of hydrophobic substrate-binding region, which was composed of Leu , Phe , and Val . Five mutants (L156A, F164A, V204A, L156A/F164A, and L156A/V204A) were generated and investigated to elucidate the roles of these hydrophobic residues in substrate specificity. This work provided valuable insights into the properties of LaAcE, and demonstrated that LaAcE could be used as a model enzyme of acetylesterase in lactic acid bacteria, making LaAcE a great candidate for industrial applications.
[Mh] Termos MeSH primário: Acetilesterase
Proteínas de Bactérias
Enzimas Imobilizadas
Lactobacillus acidophilus
Modelos Moleculares
Mutação de Sentido Incorreto
[Mh] Termos MeSH secundário: Acetilesterase/química
Acetilesterase/genética
Substituição de Aminoácidos
Proteínas de Bactérias/química
Proteínas de Bactérias/genética
Enzimas Imobilizadas/química
Enzimas Imobilizadas/genética
Lactobacillus acidophilus/enzimologia
Lactobacillus acidophilus/genética
Especificidade por Substrato/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Enzymes, Immobilized); EC 3.1.1.6 (Acetylesterase)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180309
[Lr] Data última revisão:
180309
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171021
[St] Status:MEDLINE


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[PMID]:27770795
[Au] Autor:Liu S; Ding S
[Ad] Endereço:College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China.
[Ti] Título:Replacement of carbohydrate binding modules improves acetyl xylan esterase activity and its synergistic hydrolysis of different substrates with xylanase.
[So] Source:BMC Biotechnol;16(1):73, 2016 10 22.
[Is] ISSN:1472-6750
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Acetylation of the xylan backbone was a major obstacle to enzymatic decomposition. Removal of acetyl groups by acetyl xylan esterases (AXEs) is essential for completely enzymatic hydrolysis of xylan. Appended carbohydrate binding modules (CBMs) can promote the enzymatic deconstruction of plant cell walls by targeting and proximity effects. Fungal acetyl xylan esterases are strictly appended to cellulose-specific CBM1. It is still unclear whether xylan-specific CBMs have a greater advantage than CBM1 in potentiating the activity of fungal deacetylating enzymes and its synergistic hydrolysis of different substrates with xylanase. RESULTS: Three recombinant AXE1s fused with different xylan-specific CBMs, together with wild-type AXE1 with CBM1 and CBM1-deleted mutant AXE1dC, were constructed in this study. The optimal temperature and pH of recombinant AXE1s was 50 °C and 8.0 (except AXE1dC-CBM6), respectively. Cellulose-specific CBM1 in AXE1 obviously contributed to its catalytic action against substrates compared with AXE1dC. However, replacement of CBM1 with xylan-specific CBM4-2 significantly enhanced AXE1 thermostability and catalytic activity against soluble substrate 4-methylumbelliferyl acetate. Whereas replacements with xylan-specific CBM6 and CBM22-2 were more effective in enzymatic release of acetic acid from destarched wheat bran, NaClO -treated wheat straw, and water-insoluble wheat arabinoxylan compared to AXE1. Moreover, replacement with CBM6 and CBM22-2 also resulted in higher degree releases of reducing sugar and acetic acid from different substrates when simultaneous hydrolysis with xylanase. A good linear relationship exists between the acetic acid and reducing sugar release. CONCLUSIONS: Our findings suggested that the replacement with CBM6 and CBM22-2 not only significantly improved the catalysis efficiency of AXE1, but also increased its synergistic hydrolysis of different substrates with xylanase, indicating the significance of targeting effect in AXE1 catalysis mediated by xylan-specific CBMs.
[Mh] Termos MeSH primário: Acetilesterase/química
Acetilesterase/genética
Endo-1,4-beta-Xilanases/química
Endo-1,4-beta-Xilanases/genética
Engenharia de Proteínas/métodos
Xilanos/química
[Mh] Termos MeSH secundário: Acetilação
Carboidratos/genética
Ativação Enzimática/genética
Estabilidade Enzimática
Redes Reguladoras de Genes/genética
Hidrólise
Complexos Multienzimáticos
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Carbohydrates); 0 (Multienzyme Complexes); 0 (Xylans); EC 3.1.1.6 (Acetylesterase); EC 3.1.1.72 (acetylxylan esterase); EC 3.2.1.8 (Endo-1,4-beta Xylanases)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:171226
[Lr] Data última revisão:
171226
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161025
[St] Status:MEDLINE


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[PMID]:28417360
[Au] Autor:Mai-Gisondi G; Master ER
[Ad] Endereço:Department of Bioproducts and Biosystems, Aalto University, 00076, Kemistintie 1, Espoo, Aalto, Finland.
[Ti] Título:Colorimetric Detection of Acetyl Xylan Esterase Activities.
[So] Source:Methods Mol Biol;1588:45-57, 2017.
[Is] ISSN:1940-6029
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Colorimetric detection of reaction products is typically preferred for initial surveys of acetyl xylan esterase (AcXE) activity. This chapter will describe common colorimetric methods, and variations thereof, for measuring AcXE activities on commercial, synthesized, and natural substrates. Whereas assays using pNP-acetate, α-naphthyl acetate, and 4-methylumbelliferyl acetate (4MUA) are emphasized, common methods used to measure AcXE activity towards carbohydrate analogs (e.g., acetylated p-nitrophenyl ß-D-xylopyranosides) and various acetylated xylans are also described. Strengths and limitations of the colorimetric assays are highlighted.
[Mh] Termos MeSH primário: Acetilesterase/química
Colorimetria/métodos
[Mh] Termos MeSH secundário: Acetilesterase/metabolismo
Ensaios Enzimáticos/métodos
Plantas/química
Especificidade por Substrato
Xilanos/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Xylans); EC 3.1.1.6 (Acetylesterase); EC 3.1.1.72 (acetylxylan esterase)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170421
[Lr] Data última revisão:
170421
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170419
[St] Status:MEDLINE
[do] DOI:10.1007/978-1-4939-6899-2_5


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[PMID]:28097692
[Au] Autor:Singh MK; Manoj N
[Ad] Endereço:Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600036, Tamil Nadu, India.
[Ti] Título:Structural role of a conserved active site cis proline in the Thermotoga maritima acetyl esterase from the carbohydrate esterase family 7.
[So] Source:Proteins;85(4):694-708, 2017 Apr.
[Is] ISSN:1097-0134
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:A conserved cis proline residue located in the active site of Thermotoga maritima acetyl esterase (TmAcE) from the carbohydrate esterase family 7 (CE7) has been substituted by alanine. The residue was known to play a crucial role in determining the catalytic properties of the enzyme. To elucidate the structural role of the residue, the crystal structure of the Pro228Ala variant (TmAcE ) was determined at 2.1 Å resolution. The replacement does not affect the overall secondary, tertiary, and quaternary structures and moderately decreases the thermal stability. However, the wild type cis conformation of the 227-228 peptide bond adopts a trans conformation in the variant. Other conformational changes in the tertiary structure are restricted to residues 222-226, preceding this peptide bond and are located away from the active site. Overall, the results suggest that the conserved proline residue is responsible for the cis conformation of the peptide and shapes the geometry of the active site. Elimination of the pyrrolidine ring results in the loss of van der Waals and hydrophobic interactions with both the alcohol and acyl moeities of the ester substrate, leading to significant impairment of the activity and perturbation of substrate specificity. Furthermore, a cis-to-trans conformational change arising out of residue changes at this position may be associated with the evolution of divergent activity, specificity, and stability properties of members constituting the CE7 family. Proteins 2017; 85:694-708. © 2016 Wiley Periodicals, Inc.
[Mh] Termos MeSH primário: Acetilesterase/química
Alanina/química
Proteínas de Bactérias/química
Prolina/química
Thermotoga maritima/enzimologia
[Mh] Termos MeSH secundário: Acetilesterase/genética
Acetilesterase/metabolismo
Alanina/metabolismo
Sequência de Aminoácidos
Substituição de Aminoácidos
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Sítios de Ligação
Biocatálise
Domínio Catalítico
Clonagem Molecular
Cristalografia por Raios X
Escherichia coli/genética
Escherichia coli/metabolismo
Expressão Gênica
Cinética
Modelos Moleculares
Mutação
Prolina/metabolismo
Ligação Proteica
Domínios e Motivos de Interação entre Proteínas
Estrutura Secundária de Proteína
Estrutura Terciária de Proteína
Proteínas Recombinantes/química
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
Alinhamento de Sequência
Homologia de Sequência de Aminoácidos
Especificidade por Substrato
Thermotoga maritima/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Recombinant Proteins); 9DLQ4CIU6V (Proline); EC 3.1.1.6 (Acetylesterase); OF5P57N2ZX (Alanine)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170726
[Lr] Data última revisão:
170726
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170119
[St] Status:MEDLINE
[do] DOI:10.1002/prot.25249


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[PMID]:27702488
[Au] Autor:Adesioye FA; Makhalanyane TP; Biely P; Cowan DA
[Ad] Endereço:Centre for Microbial Ecology and Genomics, Genomics Research Institute, Natural Sciences 2 Building, University of Pretoria, Hatfield 0028, Pretoria, South Africa.
[Ti] Título:Phylogeny, classification and metagenomic bioprospecting of microbial acetyl xylan esterases.
[So] Source:Enzyme Microb Technol;93-94:79-91, 2016 Nov.
[Is] ISSN:1879-0909
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Acetyl xylan esterases (AcXEs), also termed xylan deacetylases, are broad specificity Carbohydrate-Active Enzymes (CAZymes) that hydrolyse ester bonds to liberate acetic acid from acetylated hemicellulose (typically polymeric xylan and xylooligosaccharides). They belong to eight families within the Carbohydrate Esterase (CE) class of the CAZy database. AcXE classification is largely based on sequence-dependent phylogenetic relationships, supported in some instances with substrate specificity data. However, some sequence-based predictions of AcXE-encoding gene identity have proved to be functionally incorrect. Such ambiguities can lead to mis-assignment of genes and enzymes during sequence data-mining, reinforcing the necessity for the experimental confirmation of the functional properties of putative AcXE-encoding gene products. Although one-third of all characterized CEs within CAZy families 1-7 and 16 are AcXEs, there is a need to expand the sequence database in order to strengthen the link between AcXE gene sequence and specificity. Currently, most AcXEs are derived from a limited range of (mostly microbial) sources and have been identified via culture-based bioprospecting methods, restricting current knowledge of AcXEs to data from relatively few microbial species. More recently, the successful identification of AcXEs via genome and metagenome mining has emphasised the huge potential of culture-independent bioprospecting strategies. We note, however, that the functional metagenomics approach is still hampered by screening bottlenecks. The most relevant recent reviews of AcXEs have focused primarily on the biochemical and functional properties of these enzymes. In this review, we focus on AcXE phylogeny, classification and the future of metagenomic bioprospecting for novel AcXEs.
[Mh] Termos MeSH primário: Acetilesterase/classificação
Acetilesterase/genética
[Mh] Termos MeSH secundário: Acetilesterase/metabolismo
Bioprospecção
Mineração de Dados
Bases de Dados de Proteínas
Extremófilos/enzimologia
Extremófilos/genética
Lignina/química
Lignina/metabolismo
Metagenômica
Filogenia
Especificidade por Substrato
Xilanos/química
Xilanos/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Xylans); 11132-73-3 (lignocellulose); 9005-53-2 (Lignin); EC 3.1.1.6 (Acetylesterase); EC 3.1.1.72 (acetylxylan esterase)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170509
[Lr] Data última revisão:
170509
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161006
[St] Status:MEDLINE


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[PMID]:27481927
[Au] Autor:Rangel A; Steenbergen SM; Vimr ER
[Ad] Endereço:Laboratory of Sialobiology, Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
[Ti] Título:Unexpected Diversity of Escherichia coli Sialate O-Acetyl Esterase NanS.
[So] Source:J Bacteriol;198(20):2803-9, 2016 Oct 15.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:UNLABELLED: The sialic acids (N-acylneuraminates) are a group of nine-carbon keto-sugars existing mainly as terminal residues on animal glycoprotein and glycolipid carbohydrate chains. Bacterial commensals and pathogens exploit host sialic acids for nutrition, adhesion, or antirecognition, where N-acetyl- or N-glycolylneuraminic acids are the two predominant chemical forms of sialic acids. Each form may be modified by acetyl esters at carbon position 4, 7, 8, or 9 and by a variety of less-common modifications. Modified sialic acids produce challenges for colonizing bacteria, because the chemical alterations to N-acetylneuraminic acid (Neu5Ac) confer increased resistance to sialidase and aldolase activities essential for the catabolism of host sialic acids. Bacteria with O-acetyl sialate esterase(s) utilize acetylated sialic acids for growth, thereby gaining a presumed metabolic advantage over competitors lacking this activity. Here, we demonstrate the esterase activity of Escherichia coli NanS after purifying it as a C-terminal HaloTag fusion. Using a similar approach, we show that E. coli strain O157:H7 Stx prophage or prophage remnants invariably include paralogs of nanS often located downstream of the Shiga-like toxin genes. These paralogs may include sequences encoding N- or C-terminal domains of unknown function where the NanS domains can act as sialate O-acetyl esterases, as shown by complementation of an E. coli strain K-12 nanS mutant and the unimpaired growth of an E. coli O157 nanS mutant on O-acetylated sialic acid. We further demonstrate that nanS homologs in Streptococcus spp. also encode active esterase, demonstrating an unexpected diversity of bacterial sialate O-acetyl esterase. IMPORTANCE: The sialic acids are a family of over 40 naturally occurring 9-carbon keto-sugars that function in a variety of host-bacterium interactions. These sugars occur primarily as terminal carbohydrate residues on host glycoproteins and glycolipids. Available evidence indicates that diverse bacterial species use host sialic acids for adhesion or as sources of carbon and nitrogen. Our results show that the catabolism of the diacetylated form of host sialic acid requires a specialized esterase, NanS. Our results further show that nanS homologs exist in bacteria other than Escherichia coli, as well as part of toxigenic E. coli prophage. The unexpected diversity of these enzymes suggests new avenues for investigating host-bacterium interactions. Therefore, these original results extend our previous studies of nanS to include mucosal pathogens, prophage, and prophage remnants. This expansion of the nanS superfamily suggests important, although as-yet-unknown, functions in host-microbe interactions.
[Mh] Termos MeSH primário: Acetilesterase/metabolismo
Proteínas de Escherichia coli/metabolismo
Escherichia coli/enzimologia
[Mh] Termos MeSH secundário: Acetilesterase/química
Acetilesterase/genética
Escherichia coli/química
Escherichia coli/genética
Escherichia coli O157/química
Escherichia coli O157/enzimologia
Escherichia coli O157/genética
Proteínas de Escherichia coli/genética
Regulação Bacteriana da Expressão Gênica
Glicoproteínas/metabolismo
Ácido N-Acetilneuramínico/metabolismo
Ácidos Neuramínicos/metabolismo
Domínios Proteicos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Escherichia coli Proteins); 0 (Glycoproteins); 0 (Neuraminic Acids); 1113-83-3 (N-glycolylneuraminic acid); EC 3.1.1.6 (Acetylesterase); EC 3.1.1.6 (sialate O-acetylesterase); GZP2782OP0 (N-Acetylneuraminic Acid)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170629
[Lr] Data última revisão:
170629
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160803
[St] Status:MEDLINE
[do] DOI:10.1128/JB.00189-16


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[PMID]:27439201
[Au] Autor:Puchart V; Agger JW; Berrin JG; Várnai A; Westereng B; Biely P
[Ad] Endereço:Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovak Republic.
[Ti] Título:Comparison of fungal carbohydrate esterases of family CE16 on artificial and natural substrates.
[So] Source:J Biotechnol;233:228-36, 2016 Sep 10.
[Is] ISSN:1873-4863
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:The enzymatic conversion of acetylated hardwood glucuronoxylan to functional food oligomers, biochemicals or fermentable monomers requires besides glycoside hydrolases enzymes liberating acetic acid esterifying position 2 and/or 3 in xylopyranosyl (Xylp) residues. The 3-O-acetyl group at internal Xylp residues substituted by MeGlcA is the only acetyl group of hardwood acetylglucuronoxylan and its fragments not attacked by acetylxylan esterases of carbohydrate esterase (CE) families 1, 4, 5 and 6 and by hemicellulolytic acetyl esterases classified in CE family 16. Monoacetylated aldotetraouronic acid 3″-Ac(3)MeGlcA(3)Xyl3, generated from the polysaccharide by GH10 endoxylanases, appears to be one of the most resistant fragments. The presence of the two substituents on the non-reducing-end Xylp residue prevents liberation of MeGlcA by α-glucuronidase of family GH67 and blocks the action of acetylxylan esterases. The Ac(3)MeGlcA(3)Xyl3 was isolated from an enzymatic hydrolysate of birchwood acetylglucuronoxylan and characterized by (1)H NMR spectroscopy as a mixture of two positional isomers, 3″-Ac(3)MeGlcA(3)Xyl3 and 4″-Ac(3)MeGlcA(3)Xyl3, the latter being the result of acetyl group migration. The mixture was used as a substrate for three members of CE16 family of fungal origin. Trichoderma reesei CE16 esterase, inactive on polymeric substrate, deacetylated both isomers. Podospora anserina and Aspergillus niger esterases, active on acetylglucuronoxylan, deesterified effectively only the 4″-isomer. The results indicate catalytic diversity among CE16 enzymes, but also their common and unifying catalytic ability to exo-deacetylate positions 3 and 4 on non-reducing-end Xylp residues, which is an important step in plant hemicellulose saccharification.
[Mh] Termos MeSH primário: Acetilesterase/metabolismo
Aspergillus niger/enzimologia
Proteínas Fúngicas/metabolismo
Madeira/metabolismo
[Mh] Termos MeSH secundário: Acetilação
Oligossacarídeos
Estereoisomerismo
Xilanos/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Fungal Proteins); 0 (Oligosaccharides); 0 (Xylans); EC 3.1.1.6 (Acetylesterase); EC 3.1.1.72 (acetylxylan esterase)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170306
[Lr] Data última revisão:
170306
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160721
[St] Status:MEDLINE


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[PMID]:27329813
[Au] Autor:Uechi K; Kamachi S; Akita H; Mine S; Watanabe M
[Ad] Endereço:Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
[Ti] Título:Crystal structure of an acetyl esterase complexed with acetate ion provides insights into the catalytic mechanism.
[So] Source:Biochem Biophys Res Commun;477(3):383-7, 2016 08 26.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:We previously reported the crystal structure of an acetyl esterase (TcAE206) belonging to carbohydrate esterase family 3 from Talaromyces cellulolyticus. In this study, we solved the crystal structure of an S10A mutant of TcAE206 complexed with an acetate ion. The acetate ion was stabilized by three hydrogen bonds in the oxyanion hole instead of a water molecule as in the structure of wild-type TcAE206. Furthermore, the catalytic triad residue His182 moved 0.8 Å toward the acetate ion upon substrate entering the active site, suggesting that this movement is necessary for completion of the catalytic reaction.
[Mh] Termos MeSH primário: Acetatos/química
Acetilesterase/química
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Catálise
Cristalografia por Raios X
Homologia de Sequência de Aminoácidos
Especificidade por Substrato
Talaromyces/enzimologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Acetates); EC 3.1.1.6 (Acetylesterase)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:171126
[Lr] Data última revisão:
171126
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160623
[St] Status:MEDLINE


  9 / 525 MEDLINE  
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[PMID]:27181355
[Au] Autor:Singh MK; Manoj N
[Ad] Endereço:Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600036, India. Electronic address: mrityunjay20nov@gmail.com.
[Ti] Título:Crystal structure of Thermotoga maritima acetyl esterase complex with a substrate analog: Insights into the distinctive substrate specificity in the CE7 carbohydrate esterase family.
[So] Source:Biochem Biophys Res Commun;476(2):63-8, 2016 07 22.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The carbohydrate esterase family 7 (CE7) members are acetyl esterases that possess unusual substrate specificity for cephalosporin C and 7-amino-cephalosporanic acid. This family containing the α/ß hydrolase fold has a distinctive substrate profile that allows it to carry out hydrolysis of esters containing diverse alcohol moieties while maintaining narrow specificity for an acetate ester. Here we investigate the structural basis of this preference for small acyl groups using the crystal structure of the thermostable Thermotoga maritima CE7 acetyl esterase (TmAcE) complexed with a non-cognate substrate analog. The structure determined at 1.86 Å resolution provides direct evidence for the location of the largely hydrophobic and rigid substrate binding pocket in this family. Furthermore, a three-helix insertion domain near the catalytic machinery shapes the substrate binding site. The structure reveals two residues (Pro228 and Ile276) which constitute a hydrophobic rigid binding surface for the acyl group of the ester and thus restricts the size of the acyl group that be accommodated. In combination with previous literature on kinetic properties of the enzyme, our studies suggest that these residues determine the unique specificity of the TmAcE for short straight chain esters. The structure provides a template for focused attempts to engineer the CE7 enzymes for enhanced stability, selectivity or activity for biocatalytic applications.
[Mh] Termos MeSH primário: Acetilesterase/química
Thermotoga maritima/enzimologia
[Mh] Termos MeSH secundário: Acetatos/química
Acetatos/metabolismo
Acetilesterase/metabolismo
Álcoois/química
Álcoois/metabolismo
Sítios de Ligação
Hidrolases de Éster Carboxílico/química
Hidrolases de Éster Carboxílico/metabolismo
Domínio Catalítico
Cristalografia por Raios X
Ésteres/química
Ésteres/metabolismo
Indóis/química
Indóis/metabolismo
Modelos Moleculares
Conformação Proteica
Especificidade por Substrato
Thermotoga maritima/química
Thermotoga maritima/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Acetates); 0 (Alcohols); 0 (Esters); 0 (Indoles); EC 3.1.1.- (Carboxylic Ester Hydrolases); EC 3.1.1.41 (cephalosporin-C deacetylase); EC 3.1.1.6 (Acetylesterase)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:171125
[Lr] Data última revisão:
171125
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160517
[St] Status:MEDLINE


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[PMID]:26991446
[Au] Autor:Oh C; Ryu BH; An DR; Nguyen DD; Yoo W; Kim T; Ngo TD; Kim HS; Kim KK; Kim TD
[Ad] Endereço:Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Korea.
[Ti] Título:Structural and Biochemical Characterization of an Octameric Carbohydrate Acetylesterase from Sinorhizobium meliloti.
[So] Source:FEBS Lett;590(8):1242-52, 2016 04.
[Is] ISSN:1873-3468
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Carbohydrate acetylesterases, which have a highly specific role among plant-interacting bacterial species, remove the acetyl groups from plant carbohydrates. Here, we determined the crystal structure of Est24, an octameric carbohydrate acetylesterase from Sinorhizobium meliloti, at 1.45 Å resolution and investigated its biochemical properties. The structure of Est24 consisted of five parallel ß strands flanked by α helices, which formed an octameric assembly with two distinct interfaces. The deacetylation activity of Est24 and its mutants around the substrate-binding pocket was investigated using several substrates, including glucose pentaacetate and acetyl alginate. Elucidation of the structure-function relationships of Est24 could provide valuable opportunities for biotechnological explorations.
[Mh] Termos MeSH primário: Acetilesterase/química
Acetilesterase/metabolismo
Carboidratos/química
Sinorhizobium meliloti/enzimologia
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Sítios de Ligação
Cristalografia por Raios X
Análise Mutacional de DNA
Cetoprofeno/metabolismo
Proteínas Mutantes/metabolismo
Multimerização Proteica
Estrutura Secundária de Proteína
Alinhamento de Sequência
Análise de Sequência de Proteína
Especificidade por Substrato
[Pt] Tipo de publicação:LETTER; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Carbohydrates); 0 (Mutant Proteins); 90Y4QC304K (Ketoprofen); EC 3.1.1.6 (Acetylesterase)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:171104
[Lr] Data última revisão:
171104
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160319
[St] Status:MEDLINE
[do] DOI:10.1002/1873-3468.12135



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