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Crystal structure and reactivity of YbdL from Escherichia coli identify a methionine aminotransferase function
Author(s) -
Dolzan Manuela,
Johansson Kenth,
Roig-Zamboni Véronique,
Campanacci Valérie,
Tegoni Mariella,
Schneider Gunter,
Cambillau Christian
Publication year - 2004
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2004.06.075
Subject(s) - pyrococcus horikoshii , biochemistry , escherichia coli , pyridoxal , active site , amino acid , enzyme , pyridoxal phosphate , lyase , transferase , chemistry , peptide sequence , residue (chemistry) , binding site , biology , cofactor , gene
The ybdL gene of Escherichia coli codes for a protein of unknown function. Sequence analysis showed moderate homology to several vitamin B 6 dependent enzymes, suggesting that it may bind pyridoxal‐5 ′ ‐phosphate. The structure analysis of YbdL to 2.35 Å resolution by protein crystallography verifies that it is a PLP dependent enzyme of fold type I, the typical aspartate aminotransferase fold. The active site contains a bound pyridoxal‐5 ′ ‐phosphate, covalently attached to the conserved active site lysine residue Lys236. The pattern of conserved amino acids in the putative substrate binding pocket of the enzyme reveals that it is most closely related to a hyperthermophilic aromatic residue aminotransferase from the archeon Pyrococcus horikoshii . Activity tests with 10 amino acids as amino‐donors reveal, however, a preference for Met, followed by His and Phe, results which can be rationalized by modelization studies.