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Crystal structure of a putative aspartate aminotransferase belonging to subgroup IV
Author(s) -
Katsura Yasuhiro,
Shirouzu Mikako,
Yamaguchi Hiroto,
Ishitani Ryuichiro,
Nureki Osamu,
Kuramitsu Seiki,
Hayashi Hideyuki,
Yokoyama Shigeyuki
Publication year - 2004
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/prot.20020
Subject(s) - thermus thermophilus , transamination , enzyme , crystal structure , biology , pyridoxal phosphate , peptide sequence , escherichia coli , biochemistry , chemistry , crystallography , cofactor , gene
Protein TT0402 from Thermus thermophilus HB8 exhibits about 30–35% sequence identity with proteins belonging to subgroup IV in the aminotransferase family of the fold‐type I pyridoxal 5′‐phosphate (PLP)‐dependent enzymes. In this study, we determined the crystal structure of TT0402 at 2.3 Å resolution ( R factor = 19.9%, R free = 23.6%). The overall structure of TT0402 exhibits the fold conserved in aminotransferases, and is most similar to that of the Escherichia coli phosphoserine aminotransferase, which belongs to subgroup IV but shares as little as 13% sequence identity with TT0402. Kinetic assays confirmed that TT0402 has higher transamination activities with the amino group donor, L ‐glutamate, and somewhat lower activities with L ‐aspartate. These results indicate that TT0402 is a subgroup IV aminotransferase for the synthesis/degradation of either L ‐aspartate or a similar compound. Proteins 2004. © 2004 Wiley‐Liss, Inc.