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<div> The genus <i>Streptomyces</i> comprises gram-positive bacteria that produce large numbers of secondary metabolites, which have promising commercial applications and deserve extensive study. Most bacteria synthesize fatty acids using a type II fatty acid synthase, with each step catalyzed by a discrete protein. Fatty acid synthesis has been intensively studied in the model strain <i>Streptomyces coelicolor</i>, in which 3-ketoacyl-acyl carrier protein synthase III (KAS III, FabH) is essential for growth and fatty acid biosynthesis. In this study, the FabH homolog SCO6564 (named FabH2) was identified in the <i>S</i>. <i>coelicolor</i> genome by BLAST analysis. The expression of <i>fabH2</i> restored the growth of <i>Ralstonia solanacearum fabH</i> mutant and made the mutant produce small amounts of branched-chain fatty acids. FabH2 could condense various substrates, including straight-chain and branched-chain acyl-CoAs, with malonyl-acyl carrier protein to initiate fatty acid synthesis in <i>in vitro</i> assays. The <i>fabH2</i> deletion did not cause significant changes in the growth or fatty acid composition of <i>S</i>. <i>coelicolor</i>, indicating that <i>fabH2</i> is nonessential for growth or fatty acid synthesis. However, <i>fabH2</i> overexpression reduced the blue-pigmented actinorhodin production. Phylogenetic analysis of KAS III from different bacteria revealed that FabH2 belongs to a novel group of FabH-type, which is ubiquitous in <i>Streptomyces</i> spp. </div>