Crystal structure analysis and enzymatic characterization of γ-glutamyltranspeptidase from Pseudomonas nitroreducens
| Autor: | Mamoru Wakayama, Masashi Imaoka, Takafumi Itoh, Yoichiro Shimizu, Takao Hibi |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Protein Conformation Stereochemistry Peptide Crystallography X-Ray Applied Microbiology and Biotechnology Biochemistry Substrate Specificity Analytical Chemistry 03 medical and health sciences chemistry.chemical_compound Hydrolysis Bacterial Proteins Catalytic Domain Pseudomonas Transferase Amino Acid Sequence Amino Acids Molecular Biology chemistry.chemical_classification Sequence Homology Amino Acid 030102 biochemistry & molecular biology biology Organic Chemistry Mutagenesis gamma-Glutamyltransferase General Medicine Pseudomonas nitroreducens Theanine biology.organism_classification Amino acid 030104 developmental biology Enzyme chemistry Mutagenesis Site-Directed Biotechnology |
| Zdroj: | Bioscience, Biotechnology, and Biochemistry. 83:262-269 |
| ISSN: | 1347-6947 0916-8451 |
| DOI: | 10.1080/09168451.2018.1547104 |
| Popis: | Theanine (γ-glutamylethylamide) is an amino acid analog that reduces blood pressure and improves immune responses. The ϒ-glutamyltranspeptidase (GGT) from Pseudomonas nitroreducens IFO12694 (PnGGT) has a unique preference for primary amines as ϒ-glutamyl acceptors over standard L-amino acids and peptides. This characteristic is useful for the synthesis of theanine. We used X-ray crystallographic analysis to understand the structural basis of PnGGT’s hydrolysis and transpeptidation reactions and to characterize its previously unidentified acceptor site. Structural studies of PnGGT have shown that key interactions between three residues (Trp385, Phe417, and Trp525) distinguish PnGGT from other GGTs. We studied the roles of these residues in the distinct biochemical properties of PnGGT using site-directed mutagenesis. All mutants showed a significant decrease in hydrolysis activity and an increase in transpeptidase activity, suggesting that the aromatic side chains of Trp385, Phe417, and Trp525 were involved in the recognition of acceptor substrates. Abbreviations: ϒ-glutamyl peptide, theanine, X-ray crystallography. |
| Databáze: | OpenAIRE |
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