7ERV
Crystal structure of L-histidine decarboxylase (C57S/C101V/C282V mutant) from Photobacterium phosphoreum
Summary for 7ERV
| Entry DOI | 10.2210/pdb7erv/pdb |
| Descriptor | Histidine decarboxylase, IMIDAZOLE (3 entities in total) |
| Functional Keywords | lyase, decarboxylase |
| Biological source | Photobacterium phosphoreum |
| Total number of polymer chains | 1 |
| Total formula weight | 42365.71 |
| Authors | Oda, Y.,Nakata, K.,Yamaguchi, H.,Kashiwagi, T.,Miyano, H.,Mizukoshi, T. (deposition date: 2021-05-07, release date: 2022-02-16, Last modification date: 2023-11-29) |
| Primary citation | Oda, Y.,Nakata, K.,Miyano, H.,Mizukoshi, T.,Yamaguchi, H.,Kashiwagi, T. Structural insights into the enhanced thermostability of cysteine substitution mutants of L-histidine decarboxylase from Photobacterium phosphoreum. J.Biochem., 171:31-40, 2022 Cited by PubMed Abstract: Enzymatic amino acid assays are important in physiological research and clinical diagnostics because abnormal amino acid concentrations in biofluids are associated with various diseases. L-histidine decarboxylase from Photobacterium phosphoreum (PpHDC) is a pyridoxal 5'-phosphate-dependent enzyme and a candidate for use in an L-histidine quantitation assay. Previous cysteine substitution experiments demonstrated that the PpHDC C57S mutant displayed improved long-term storage stability and thermostability when compared with those of the wild-type enzyme. In this study, combinational mutation experiments of single cysteine substitution mutants of PpHDC were performed, revealing that the PpHDC C57S/C101V/C282V mutant possessed the highest thermostability. The stabilizing mechanism of these mutations was elucidated by solving the structures of PpHDC C57S and C57S/C101V/C282V mutants by X-ray crystallography. In the crystal structures, two symmetry-related PpHDC molecules form a domain-swapped homodimer. The side chain of S57 is solvent exposed in the structure, indicating that the C57S mutation eliminates chemical oxidation or disulfide bond formation with a free thiol group, thereby providing greater stability. Residues 101 and 282 form hydrophobic interactions with neighboring hydrophobic residues. Mutations C101V and C282V enhanced thermostability of PpHDC by filling a cavity present in the hydrophobic core (C101V) and increasing hydrophobic interactions. PubMed: 34622278DOI: 10.1093/jb/mvab103 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.5 Å) |
Structure validation
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