3kof

Crystal structure of the double mutant F178Y/R181E of E.coli transaldolase B

spinqualitylabelsall models 3kof, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3kof is a 2 chain structure with sequence from Escherichia coli K-12. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.9Å Ligands: SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function TALB_ECOLI Transaldolase is important for the balance of metabolites in the pentose-phosphate pathway.[HAMAP-Rule:MF_00492] 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 Recently, we reported on a transaldolase B variant (TalB F178Y) that is able to use dihydroxyacetone (DHA) as donor in aldol reactions. In a second round of protein engineering, we aimed at improving the affinity of this variant towards nonphosphorylated acceptor aldehydes, that is, glyceraldehyde (GA). The anion binding site was identified in the X-ray structure of TalB F178Y where a sulfate ion from the buffer was bound in the active site. Therefore, we performed site-directed saturation mutagenesis at three residues forming the putative phosphate binding site, Arg181, Ser226 and Arg228. The focused libraries were screened for the formation of D-fructose from DHA and d,l-GA by using an adjusted colour assay. The best results with respect to the synthesis of D-fructose were achieved with the TalB F178Y/R181E variant, which exhibited an at least fivefold increase in affinity towards d,l-GA (K(M)=24 mM). We demonstrated that this double mutant can use D-GA, glycolaldehyde and the L-isomer, L-GA, as acceptor substrates. This resulted in preparative synthesis of D-fructose, D-xylulose and L-sorbose when DHA was used as donor. Hence, we engineered a DHA-dependent aldolase that can synthesise the formation of polyhydroxylated compounds from simple and cheap substrates at preparative scale. Redesigning the Active Site of Transaldolase TalB from Escherichia coli: New Variants with Improved Affinity towards Nonphosphorylated Substrates.,Schneider S, Gutierrez M, Sandalova T, Schneider G, Clapes P, Sprenger GA, Samland AK Chembiochem. 2010 Feb 10. PMID:20148428 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Transaldolase 3D structures

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