2dh6 | pdb_00002dh6

Crystal structure of E. coli Apo-TrpB

spinqualitylabelsall models 2dh6, resolution 3.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2dh6 is a 1 chain structure with sequence from "bacillus_coli"_migula_1895 "bacillus coli" migula 1895. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: SO4 Related: 2dh5 Activity: Tryptophan synthase, with EC number 4.2.1.20 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT, TOPSAN Function [TRPB_ECOLI] The beta subunit is responsible for the synthesis of L-tryptophan from indole and L-serine.[HAMAP-Rule:MF_00133] 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 To understand the basis for the lower activity of the tryptophan synthase beta(2) subunit in comparison to the alpha(2)beta(2) complex, we determined the crystal structures of apo-beta(2) and holo-beta(2) from Escherichia coli at 3.0 and 2.9 A resolutions, respectively. To our knowledge, this is the first report of both beta(2) subunit structures with and without pyridoxal-5'-phosphate. The apo-type molecule retained a dimeric form in solution, as in the case of the holo-beta(2) subunit. The subunit structures of both the apo-beta(2) and the holo-beta(2) forms consisted of two domains, namely the N domain and the C domain. Although there were significant structural differences between the apo- and holo-structures, they could be easily superimposed with a 22 degrees rigid body rotation of the C domain. The pyridoxal-5'-phosphate-bound holo-form had multiple interactions between the two domains and a long loop (residues 260-310), which were missing in the apo-form. Comparison of the structures of holo-Ecbeta(2) and Stbeta(2) in the alpha(2)beta(2) complex from Salmonella typhimurium (Stalpha(2)beta(2)) identified the cause of the lower enzymatic activity of holo-Ecbeta(2) in comparison with Stalpha(2)beta(2). The substrate (indole) gate residues, Tyr279 and Phe280, block entry of the substrate into the beta(2) subunit, although the indole can directly access the active site as a result of a wider cleft between the N and C domains in the holo-Ecbeta(2) subunit. In addition, the structure around betaAsp305 of the holo-Ecbeta(2) subunit was similar to the open state of Stalpha(2)beta(2) with low activity, resulting in lower activity of holo-Ecbeta(2). Large conformational changes in the Escherichia coli tryptophan synthase beta(2) subunit upon pyridoxal 5'-phosphate binding.,Nishio K, Ogasahara K, Morimoto Y, Tsukihara T, Lee SJ, Yutani K FEBS J. 2010 May;277(9):2157-70. Epub 2010 Mar 27. PMID:20370823 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Tryptophan synthase 3D structures

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