The two putative transcription factors FPSE_09188 and FPSE_09189 could be responsible for orchestrating expression of the W493 A and B biosynthesis cluster genes (Probable). W493 A and B consist of six amino acid residues D-allo-thr, L-Ala, D-Ala, L-Gln, D-Tyr, and L-Val/L-Ile linked to a 3-hydroxy-4-methyltetradecanoic acid polyketide chain