1bw0 | pdb_00001bw0

CRYSTAL STRUCTURE OF TYROSINE AMINOTRANSFERASE FROM TRYPANOSOMA CRUZI

spinqualitylabelsall models 1bw0, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1bw0 is a 2 chain structure with sequence from Trycr. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. NonStd Res: LLP Activity: Tyrosine transaminase, with EC number 2.6.1.5 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum Function [ATTY_TRYCR] Transaminase involved in tyrosine breakdown. Converts tyrosine to p-hydroxyphenylpyruvate (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The crystal structure of tyrosine aminotransferase (TAT) from the parasitic protozoan Trypanosoma cruzi, which belongs to the aminotransferase subfamily Igamma, has been determined at 2.5 A resolution with the R-value R = 15.1%. T. cruzi TAT shares less than 15% sequence identity with aminotransferases of subfamily Ialpha but shows only two larger topological differences to the aspartate aminotransferases (AspATs). First, TAT contains a loop protruding from the enzyme surface in the larger cofactor-binding domain, where the AspATs have a kinked alpha-helix. Second, in the smaller substrate-binding domain, TAT has a four-stranded antiparallel beta-sheet instead of the two-stranded beta-sheet in the AspATs. The position of the aromatic ring of the pyridoxal-5'-phosphate cofactor is very similar to the AspATs but the phosphate group, in contrast, is closer to the substrate-binding site with one of its oxygen atoms pointing toward the substrate. Differences in substrate specificities of T. cruzi TAT and subfamily Ialpha aminotransferases can be attributed by modeling of substrate complexes mainly to this different position of the cofactor-phosphate group. Absence of the arginine, which in the AspATs fixes the substrate side-chain carboxylate group by a salt bridge, contributes to the inability of T. cruzi TAT to transaminate acidic amino acids. The preference of TAT for tyrosine is probably related to the ability of Asn17 in TAT to form a hydrogen bond to the tyrosine side-chain hydroxyl group. Crystal structure of Trypanosoma cruzi tyrosine aminotransferase: substrate specificity is influenced by cofactor binding mode.,Blankenfeldt W, Nowicki C, Montemartini-Kalisz M, Kalisz HM, Hecht HJ Protein Sci. 1999 Nov;8(11):2406-17. PMID:10595543 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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