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B6db references: 15007066

type Journal Article
authors Fernandez FJ, Vega MC, Lehmann F, Sandmeier E, Gehring H, Christen P, Wilmanns M.
title Structural studies of the catalytic reaction pathway of a hyperthermophilic histidinol-phosphate aminotransferase.
journal J Biol Chem
Activity 2.6.1.9
Family 2.6.1.9
sel selected
ui 15007066
year (2004)
volume 279
number 20
pages 21478-88
 
abstract In histidine biosynthesis, histidinol-phosphate aminotransferase catalyzes the transfer of the amino group from glutamate to imidazole acetol-phosphate producing 2-oxoglutarate and histidinol phosphate. In some organisms such as the hyperthermophile Thermotoga maritima, specific tyrosine and aromatic amino acid transaminases have not been identified to date, suggesting an additional role for histidinol-phosphate aminotransferase in other transamination reactions generating aromatic amino acids. To gain insight into the specific function of this transaminase, we have determined its crystal structure in the absence of any ligand except phosphate, in the presence of covalently bound pyridoxal 5'-phosphate, of the coenzyme histidinol phosphate adduct, and of pyridoxamine 5'-phosphate. The enzyme accepts histidinol phosphate, tyrosine, tryptophan, and phenylalanine, but not histidine, as substrates. The structures provide a model of how these different substrates could be accommodated by histidinol-phosphate aminotransferase. Some of the structural features of the enzyme are more preserved between the T. maritima enzyme and a related threonine-phosphate decarboxylase from S. typhimurium than with histidinol-phosphate aminotransferases from different organisms.
last changed 2007/10/26 19:21

B6db references