The present invention provides for a polyketide synthase (PKS) capable of synthesizing a 3-hydroxycarboxylic acid or ketone. The present invention also provides for a host cell comprising the PKS and when cultured produces the 3-hydroxycarboxylic acid or ketone.
STATEMENT OF GOVERNMENTAL SUPPORT
 This invention was made with government support under Contract No. DE-ACO2-05CH11231 awarded by the United States Department of Energy. The government has certain rights in the invention.