An atypical 3-ketoacyl ACP synthase III required for acyl homoserine lactone synthesis in Pseudomonas syringae pv. syringae B728a.

ABSTRACT: The last step of the initiation phase of fatty acid biosynthesis in most bacteria is catalyzed by the 3-ketoacyl-acyl carrier protein (ACP) synthase III (FabH). Pseudomonas syringae pv. syringae strain B728a encodes two FabH homologs, Psyr_3467 and Psyr_3830, which we designated PssFabH1 and PssFabH2, respectively. Here, we explored the roles of these two 3-ketoacyl-ACP synthase (KAS) III proteins. We found that PssFabH1 is similar to the Escherichia coli FabH in using acetyl-acetyl-coenzyme A (CoA ) as a substrate in vitro, whereas PssFabH2 uses acyl-CoAs (C₄-C₁₀) or acyl-ACPs (C₆-C₁₀). Mutant analysis showed that neither KAS III protein is essential for the de novo fatty acid synthesis and cell growth. Loss of

SUBMITTER: Guo Q 

PROVIDER: S-EPMC10952384 | biostudies-literature | 2024 Mar

REPOSITORIES: biostudies-literature