4axk | pdb_00004axk

CRYSTAL STRUCTURE OF subHisA from the thermophile Corynebacterium efficiens

spinqualitylabelsall models 4axk, resolution 2.25Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4axk is a 2 chain structure with sequence from Aj 12310. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: GOL Activity: 1-(5-phosphoribosyl)-5- ((5-phosphoribosylamino)methylideneamino)imidazole-4-carboxamide isomerase, with EC number 5.3.1.16 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed Despite the prominent role of horizontal gene transfer (HGT) in shaping bacterial metabolism, little is known about the impact of HGT on the evolution of enzyme function. Specifically, what is the influence of a recently acquired gene on the function of an existing gene? For example, certain members of the genus Corynebacterium have horizontally acquired a whole l-tryptophan biosynthetic operon, whereas in certain closely related actinobacteria, for example, Mycobacterium, the trpF gene is missing. In Mycobacterium, the function of the trpF gene is performed by a dual-substrate (betaalpha)8 phosphoribosyl isomerase (priA gene) also involved in l-histidine (hisA gene) biosynthesis. We investigated the effect of a HGT-acquired TrpF enzyme upon PriA's substrate specificity in Corynebacterium through comparative genomics and phylogenetic reconstructions. After comprehensive in vivo and enzyme kinetic analyses of selected PriA homologs, a novel (betaalpha)8 isomerase subfamily with a specialized function in l-histidine biosynthesis, termed subHisA, was confirmed. X-ray crystallography was used to reveal active-site mutations in subHisA important for narrowing of substrate specificity, which when mutated to the naturally occurring amino acid in PriA led to gain of function. Moreover, in silico molecular dynamic analyses demonstrated that the narrowing of substrate specificity of subHisA is concomitant with loss of ancestral protein conformational states. Our results show the importance of HGT in shaping enzyme evolution and metabolism. Evolution of substrate specificity in a recipient's enzyme following horizontal gene transfer.,Noda-Garcia L, Camacho-Zarco AR, Medina-Ruiz S, Gaytan P, Carrillo-Tripp M, Fulop V, Barona-Gomez F Mol Biol Evol. 2013 Sep;30(9):2024-34. doi: 10.1093/molbev/mst115. Epub 2013 Jun , 25. PMID:23800623 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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