4w61

Crystal structure of beta-ketoacyl thiolase B (BktB) from Ralstonia eutrophaCrystal structure of beta-ketoacyl thiolase B (BktB) from Ralstonia eutropha

Structural highlights 4w61 is a 16 chain structure with sequence from Cupriavidus necator H16. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.01Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function BKTB_CUPNH Required for efficient production of poly(beta-hydroxybutyrate-co-beta-hydroxyvalerate) (PHBV). Catalyzes the condensation of acetyl-CoA and propionyl-CoA to form beta-ketovaleryl-CoA, and the condensation of two acetyl-CoA molecules to form acetoacetyl-CoA. Publication Abstract from PubMed Thiolases catalyze the formation of carbon-carbon bonds in diverse biosynthetic pathways. The promiscuous beta-ketoacyl thiolase B of Ralstonia eutropha (ReBktB) has been utilized in the in vivo conversion of Coenzyme A (CoA)-linked precursors such as acetyl-CoA and glycolyl-CoA into beta-hydroxy acids, including the pharmaceutically-important 3,4-dihydroxybutyric acid. Such thiolases could serve as powerful carbon-carbon bond-forming biocatalysts in vitro if handles less costly than CoA were employable. Here, thiolase activity is demonstrated toward substrates linked to the readily-available CoA mimic, N-acetylcysteamine (NAC). ReBktB was observed to catalyze the retro-Claisen condensation of several beta-ketoacyl-S-NAC substrates, with a preference for 3-oxopentanoyl-S-NAC over 3-oxobutanoyl-, 3-oxohexanoyl-, and 3-oxoheptanoyl-S-NAC. A 2.0 A-resolution crystal structure, in which the asymmetric unit consists of four ReBktB tetramers, provides insight into acyl group specificity and how it may be engineered. By replacing an active site methionine with an alanine, a mutant possessing significant activity towards alpha-methyl substituted, NAC-linked substrates was engineered. The ability of ReBktB and its engineered mutants to utilize NAC-linked substrates will facilitate the in vitro biocatalytic synthesis of diketide chiral building blocks from feedstock molecules such as acetate and propionate. Coenzyme A-free activity, crystal structure, and rational engineering of a promiscuous beta-ketoacyl thiolase from Ralstonia eutropha.,Fage CD, Meinke JL, Keatinge-Clay AT J Mol Catal B Enzym. 2015 Nov 1;121:113-121. doi: 10.1016/j.molcatb.2015.08.007. PMID:26494979 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Thiolase 3D structures

spinqualitylabelsall models 4w61, resolution 2.01Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image