Skip to main content
. Author manuscript; available in PMC: 2012 May 1.
Published in final edited form as: FEMS Microbiol Rev. 2011 Jan 19;35(3):475–497. doi: 10.1111/j.1574-6976.2010.00259.x

Fig. 2. Comparative model of fatty acid biosynthesis in actinomycetes.

Fig. 2

Streptomyces Corynebacterium and Mycobacterium share the initiation step for fatty acid biosynthesis which is the carboxylation of acetyl-CoA to produce malonyl-CoA, catalyzed by the ACCase complex (brown). Both in Mycobacterium and Corynebacterium spp., malonyl-CoA and acetyl-CoA are condensed to be utilized by the multifunctional type I FAS for de novo biosynthesis of fatty acids (green). In Streptomyces, malonyl-CoA is converted to malonyl-ACP by FabD and then condensed with acetyl-CoA by FabH to form β-ketoacyl-ACP, which is used by the type II FAS dissociated system for de novo biosynthesis of fatty acids (red). Both in FAS I and FAS II systems, the chain elongation steps consist of an iterative series of reactions built on successive addition of a two-carbon unit to a nascent acyl group, and reaction intermediates are covalently attached to the acyl carrier protein (ACP). In Mycobacterium both systems are present, FAS I for de novo fatty acid biosynthesis and FAS II for the elongation of fatty acids for mycolic acid production. The differential features of Mycobacterium are shown in yellow.