5h3b

Crystal Structure of SeMet-BioG from Haemophilus influenzae at 1.49 Angstroms resolution

spinqualitylabelsall models 5h3b, resolution 1.49Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5h3b is a 2 chain structure with sequence from Haemophilus influenzae Rd KW20. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.492Å Ligands: GOL, IPA, MSE Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Y1552_HAEIN Publication Abstract from PubMed Pimeloyl-acyl carrier protein (ACP) methyl esterase is an alpha/beta-hydrolase that catalyzes the last biosynthetic step of pimeloyl-ACP, a key intermediate in biotin biosynthesis. Intriguingly, multiple nonhomologous isofunctional forms of this enzyme that lack significant sequence identity are present in diverse bacteria. One such esterase, Escherichia coli BioH, has been shown to be a typical alpha/beta-hydrolase fold enzyme. To gain further insights into the role of this step in biotin biosynthesis, we have determined the crystal structure of another widely distributed pimeloyl-ACP methyl esterase, Haemophilus influenzae BioG, at 1.26 A. The BioG structure is similar to the BioH structure and is composed of an alpha-helical lid domain and a core domain that contains a central seven-stranded beta-pleated sheet. However, four of the six alpha-helices that flank both sides of the BioH core beta-sheet are replaced with long loops in BioG, thus forming an unusual alpha/beta-hydrolase fold. This structural variation results in a significantly decreased thermal stability of the enzyme. Nevertheless, the lid domain and the residues at the lid-core interface are well conserved between BioH and BioG, in which an analogous hydrophobic pocket for pimelate binding as well as similar ionic interactions with the ACP moiety are retained. Biochemical characterization of site-directed mutants of the residues hypothesized to interact with the ACP moiety supports a similar substrate interaction mode for the two enzymes. Consequently, these enzymes package the identical catalytic function under a considerably different protein surface. An Atypical alpha/beta-Hydrolase Fold Revealed in the Crystal Structure of Pimeloyl-Acyl Carrier Protein Methyl Esterase BioG from Haemophilus influenzae.,Shi J, Cao X, Chen Y, Cronan JE, Guo Z Biochemistry. 2016 Dec 6;55(48):6705-6717. Epub 2016 Nov 21. PMID:27933801 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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