Crystal structures of L201A mutant of D-amino acid aminotransferase at 2.0 A resolution: implication of the structural role of Leu201 in transamination
| Autor: | Daniel Peisach, Nobuyoshi Esaki, Gregory A. Petsko, Tohru Yoshimura, Kazuhisa Kishimoto, Dagmar Ringe, Shigetoshi Sugio, A. Kashima |
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| Rok vydání: | 1998 |
| Předmět: |
Models
Molecular Protein Conformation Stereochemistry Transamination Mutant Bioengineering Crystallography X-Ray Biochemistry D-Alanine Transaminase chemistry.chemical_compound Residue (chemistry) Leucine Transferase Binding site Molecular Biology Pyridoxal chemistry.chemical_classification Alanine Binding Sites Alanine Transaminase Enzyme Activation Enzyme chemistry Mutation Ketoglutaric Acids Pyridoxamine Biotechnology |
| Zdroj: | Protein Engineering Design and Selection. 11:613-619 |
| ISSN: | 1741-0134 1741-0126 |
| DOI: | 10.1093/protein/11.8.613 |
| Popis: | The leucine-to-alanine mutation at residue 201 of D-amino acid aminotransferase provides a unique enzyme which gradually loses its activity while catalyzing the normal transamination; the co-enzyme form is converted from pyridoxal 5'-phosphate to pyridoxamine 5'-phosphate upon the inactivation [Kishimoto,K., Yoshimura,T., Esaki,N., Sugio,S., Manning,J.M. and Soda,K. (1995) J. Biochem., 117, 691-696]. Crystal structures of both co-enzyme forms of the mutant enzyme have been determined at 2.0 A resolution: they are virtually identical, and are quite similar to that of the wild-type enzyme. Significant differences in both forms of the mutant are localized only on the bound co-enzyme, the side chains of Lys145 and Tyr31, and a water molecule sitting on the putative substrate binding site. Detailed comparisons of the structures of the mutant, together with that of the pyridoxamine-5'-phosphate form of the wild-type enzyme, imply that Leu201 would play a crucial role in the transamination reaction by keeping the pyridoxyl ring in the proper location without disturbing its oscillating motion, although the residue seems to not be especially important for the structural integrity of the enzyme. |
| Databáze: | OpenAIRE |
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