7F27
Crystal structure of polyketide ketosynthase
Summary for 7F27
| Entry DOI | 10.2210/pdb7f27/pdb |
| Descriptor | 3-oxoacyl-(Acyl-carrier-protein) synthase (2 entities in total) |
| Functional Keywords | thiolase fold, ketosynthase, ligase |
| Biological source | Acinetobacter baumannii (strain ACICU) |
| Total number of polymer chains | 4 |
| Total formula weight | 174990.98 |
| Authors | |
| Primary citation | Lee, W.C.,Choi, S.,Jang, A.,Yeon, J.,Hwang, E.,Kim, Y. Structural basis of the complementary activity of two ketosynthases in aryl polyene biosynthesis. Sci Rep, 11:16340-16340, 2021 Cited by PubMed Abstract: Aryl polyenes (APE) are one of the most widespread secondary metabolites among gram-negative bacteria. In Acinetobacter baumannii, strains belonging to the virulent global clone 2 (GC2) mostly contain APE biosynthesis genes; its relevance in elevated pathogenicity is of great interest. APE biosynthesis gene clusters harbor two ketosynthases (KSs): the heterodimeric KS-chain length factor complex, ApeO-ApeC, and the homodimeric ketoacyl-acyl carrier protein synthase I (FabB)-like KS, ApeR. The role of the two KSs in APE biosynthesis is unclear. We determined the crystal structures of the two KSs from a pathogenic A. baumannii strain. ApeO-ApeC and ApeR have similar cavity volumes; however, ApeR has a narrow cavity near the entrance. In vitro assay based on the absorption characteristics of polyene species indicated the generation of fully elongated polyene with only ApeO-ApeC, probably because of the funnel shaped active site cavity. However, adding ApeR to the reaction increases the throughput of APE biosynthesis. Mutagenesis at Tyr135 in the active site cavity of ApeR reduces the activity significantly, which suggests that the stacking of the aryl group between Tyr135 and Phe202 is important for substrate recognition. Therefore, the two KSs function complementarily in the generation of APE to enhance its production. PubMed: 34381152DOI: 10.1038/s41598-021-95890-y PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.806 Å) |
Structure validation
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