8VDB

Crystal structure of Bacillus subtilis FabHB, beta-ketoacyl carrier protein synthase III

8VDB の概要

• エントリーDOI: 10.2210/pdb8vdb/pdb
• 分子名称: Beta-ketoacyl-[acyl-carrier-protein] synthase III 2, GLYCEROL (3 entities in total)
• 機能のキーワード: fatty acid biosynthesis, fasii, condensing enzyme, transferase
• 由来する生物種: Bacillus subtilis
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 150818.87

構造登録者

Radka, C.D.,Rock, C.O. (登録日: 2023-12-14, 公開日: 2024-02-14)

主引用文献

Radka, C.D.,Rock, C.O.
Crystal structures of the fatty acid biosynthesis initiation enzymes in Bacillus subtilis.
J.Struct.Biol., 216:108065-108065, 2024

PubMed Abstract: Bacteria use the fatty acid composition of membrane lipids to maintain homeostasis of the bilayer. β-Ketoacyl-ACP synthase III (FabH) initiates fatty acid biosynthesis and is the primary determinant of the fatty acid composition. FabH condenses malonyl-acyl carrier protein with an acyl-Coenzyme A primer to form β -ketoacyl-acyl carrier protein which is used to make substrates for lipid synthesis. The acyl-Coenzyme A primer determines whether an acyl chain in the membrane has iso, anteiso, or no branching (straight chain) and biophysical properties of the membrane. The soil bacterium Bacillus subtilis encodes two copies of FabH (BsFabHA and BsFabHB), and here we solve their crystal structures. The substrate-free 1.85 Å and 2.40 Å structures of BsFabHA and BsFabHB show both enzymes have similar residues that line the active site but differ in the architecture surrounding the catalytic residues and oxyanion hole. Branching in the BsFabHB active site may better accommodate the structure of an iso-branched acyl-Coenzyme A molecule and thus confer superior utilization to BsFabHA for this primer type. The 2.02 Å structure of BsFabHA•Coenzyme A shows how the active site architecture changes after binding the first substrate. The other notable difference is an amino acid insertion in BsFabHB that extends a cap that covers the dimer interface. The cap topology is diverse across FabH structures and appears to be a distinguishing feature. FabH enzymes have variable sensitivity to natural product inhibitors and the availability of crystal structures help clarify how nature designs antimicrobials that differentially target FabH homologs.

PubMed: 38310992
DOI: 10.1016/j.jsb.2024.108065

実験手法

X-RAY DIFFRACTION (2.4 Å)