[PMID]: | 28744579 |
[Au] Autor: | Uda K; Abe K; Dehara Y; Mizobata K; Edashige Y; Nishimura R; Radkov AD; Moe LA |
[Ad] Endereço: | Laboratory of Biochemistry, Faculty of Science and Technology, Kochi University, Kochi, 780-8520, Japan. k-uda@kochi-u.ac.jp. |
[Ti] Título: | Triple serine loop region regulates the aspartate racemase activity of the serine/aspartate racemase family. |
[So] Source: | Amino Acids;49(10):1743-1754, 2017 10. |
[Is] ISSN: | 1438-2199 |
[Cp] País de publicação: | Austria |
[La] Idioma: | eng |
[Ab] Resumo: | Recently, we cloned and characterized eleven serine and aspartate racemases (SerR and AspR, respectively) from animals. These SerRs and AspRs are not separated by their racemase functions and form a serine/aspartate racemase family cluster based on phylogenetic analysis. Moreover, we have proposed that the AspR-specific triple serine loop region at amino acid positions 150-152 may be responsible for the large AspR activity. In the present study, to test this hypothesis, we prepared and characterized fourteen mutants in this region of animal SerRs and AspRs. The large AspR activity in Acropora and Crassostrea AspR was reduced to <0.04% of wild-type after substitution of the triple serine loop region. Conversely, introducing the triple serine loop region into Acropora, Crassostrea, and Penaeus SerR drastically increased the AspR activity. Those mutants showed similar or higher substrate affinity for aspartate than serine and showed 11-683-fold higher k and 28-351-fold higher k /K values for aspartate than serine racemization. Furthermore, we introduced serine residues in all combinations at position 150-152 in mouse SerR. These mutants revealed that a change in the enzyme function from SerR to AspR can be caused by introduction of Ser151 and Ser152, and addition of the third serine residue at position 150 further enhances the enzyme specificity for aspartate due to a decrease in the serine racemase and serine dehydratase activity. Here, we provide convincing evidence that the AspR gene has evolved from the SerR gene by acquisition of the triple serine loop region. |
[Mh] Termos MeSH primário: |
Isomerases de Aminoácido Antozoários Proteínas de Artrópodes Crassostrea Mutação de Sentido Incorreto Penaeidae Racemases e Epimerases
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[Mh] Termos MeSH secundário: |
Isomerases de Aminoácido/química Isomerases de Aminoácido/genética Substituição de Aminoácidos Animais Antozoários/enzimologia Antozoários/genética Proteínas de Artrópodes/química Proteínas de Artrópodes/genética Crassostrea/enzimologia Crassostrea/genética Camundongos Penaeidae/enzimologia Penaeidae/genética Estrutura Secundária de Proteína Racemases e Epimerases/química Racemases e Epimerases/genética
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[Pt] Tipo de publicação: | JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T |
[Nm] Nome de substância:
| 0 (Arthropod Proteins); EC 5.1.- (Racemases and Epimerases); EC 5.1.1.- (Amino Acid Isomerases); EC 5.1.1.13 (aspartate racemase); EC 5.1.1.16 (serine racemase) |
[Em] Mês de entrada: | 1801 |
[Cu] Atualização por classe: | 180305 |
[Lr] Data última revisão:
| 180305 |
[Sb] Subgrupo de revista: | IM |
[Da] Data de entrada para processamento: | 170727 |
[St] Status: | MEDLINE |
[do] DOI: | 10.1007/s00726-017-2472-8 |
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