Crystallization and preliminary crystallographic analysis of the Escherichia coli tyrosine aminotransferase

Tzu-Ping Ko, Szu-Pei Wu, Wei-Zen Yang, Hsin Tsai and Hanna S. Yuan

SUMMARY 

Tyrosine aminotransferase catalyzes transamination for both dicar-boxylic and aromatic amino-acid substrates. The substrate-free Escherichia coli tyrosine aminotransferase (eTAT) bound with the cofactor pyridoxal 50 -phosphate (PLP) was crystallized in the trigonal space group P32 . A low-resolution crystal structure of eTAT was determined by molecular-replacement methods. The overall folding of eTAT resembles that of the aspartate aminotransferases, with the two identical subunits forming a dimer in which each monomer binds a PLP molecule via a covalent bond linked to the e-NH2 group of Lys258. Comparison of the structure of eTATwith those of the open, half-open or closed form of chicken or E. coli aspartate aminotransferases shows the eTAT structure to be in the open conformation.

Acta Cryst. (1999). D55, 1474-1477