Preliminary kinetic analysis of acyl carrier protein-ketoacylsynthase interactions in the actinorhodin minimal polyketide synthase.

Interactions between the acyl carrier protein (ACP) and ketoacylsynthase (KS) components of the actinorhodin polyketide synthase have been investigated using kinetic assays. These indicate that for three different quantifiable interactions (acceleration of self-malonylation, initiation and extension) mutations of E47 and E53 residues located on ACP helix II have different effects. Initiation clearly involves interaction between KS(beta) and ACP helix II, but self-malonylation acceleration and extension by KS(alpha) appear not to be affected strongly by the same mutations.