1jhm

Three-dimensional Structure of CobT in Complex with 5-methylbenzimidazoleThree-dimensional Structure of CobT in Complex with 5-methylbenzimidazole

Structural highlights 1jhm is a 1 chain structure with sequence from "bacillus_cholerae-suis"_smith_1894 "bacillus cholerae-suis" smith 1894. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: , Related: 1d0s, 1d0v, 1jha, 1jhx, 1jhu, 1jh8, 1jhy, 1jhp, 1jhv, 1jhr, 1jhq, 1jho Activity: Nicotinate-nucleotide--dimethylbenzimidazole phosphoribosyltransferase, with EC number 2.4.2.21 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [COBT_SALTY] Catalyzes the synthesis of alpha-ribazole-5'-phosphate from nicotinate mononucleotide (NAMN) and 5,6-dimethylbenzimidazole (DMB). 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 Nicotinate mononucleotide (NaMN):5,6-dimethylbenzimidazole phosphoribosyltransferase (CobT) from Salmonella enterica plays a central role in the synthesis of alpha-ribazole, a key component of the lower ligand of cobalamin. Surprisingly, CobT can phosphoribosylate a wide range of aromatic substrates, giving rise to a wide variety of lower ligands in cobamides. To understand the molecular basis for this lack of substrate specificity, the x-ray structures of CobT complexed with adenine, 5-methylbenzimidazole, 5-methoxybenzimidazole, p-cresol, and phenol were determined. Furthermore, adenine, 5-methylbenzimidazole, 5-methoxybenzimidazole, and 2-hydroxypurine were observed to react with NaMN within the crystal lattice and undergo the phosphoribosyl transfer reaction to form product. Significantly, the stereochemistries of all products are identical to those found in vivo. Interestingly, p-cresol and phenol, which are the lower ligand in Sporomusa ovata, bound to CobT but did not react with NaMN. This study provides a structural explanation for how CobT can phosphoribosylate most of the commonly observed lower ligands found in cobamides with the exception of the phenolic lower ligands observed in S. ovata. This is accomplished with minor conformational changes in the side chains that constitute the 5,6-dimethylbenzimidazole binding site. These investigations are consistent with the implication that the nature of the lower ligand is controlled by metabolic factors rather by the specificity of the phosphoribosyltransferase. Structural investigation of the biosynthesis of alternative lower ligands for cobamides by nicotinate mononucleotide: 5,6-dimethylbenzimidazole phosphoribosyltransferase from Salmonella enterica.,Cheong CG, Escalante-Semerena JC, Rayment I J Biol Chem. 2001 Oct 5;276(40):37612-20. Epub 2001 Jul 5. PMID:11441022 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Phosphoribosyltransferase

spinqualitylabelsall models 1jhm, resolution 2.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image