Enzymes for producing non-straight-chain fatty acids, microorganisms comprising the enzymes, and in vivo and in vitro uses of the enzymes. Provided are enzymes capable of producing various non-straight-chain fatty acids, including branched-chain fatty acids, cyclic fatty acids, and furan-containing fatty acids. The enzymes include RSP2144, RSP1091, and RSP1090 from Rhodobacter sphaeroides and homologs thereof. The enzymes can be purified to produce non-straight-chain fatty acids in vitro or expressed in microorganisms to produce non-straight-chain fatty acids in vivo. The microorganisms can be fine-tuned to produce a specific type of non-straight-chain fatty acid by expressing, overexpressing, or deleting the enzymes in various combinations.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
 This invention was made with government support under DE-FC02-07ER64494 awarded by the US Department of Energy and GM107199 and GM075273 awarded by the National Institutes of Health. The government has certain rights in the invention.