Function of lanI in regulation of landomycin A biosynthesis in Streptomyces cyanogenus S136 and cross-complementation studies with Streptomyces antibiotic regulatory proteins encoding genes.

The transcriptional regulator of landomycin A biosynthesis encoded by lanI gene has been inactivated within the chromosome of Streptomyces cyanogenus S136. The obtained mutant strain did not produce landomycin A and its known intermediates. Loss of landomycin A production caused significant changes in morphology of the lanI deficient strain.

A putative proteinase gene is involved in regulation of landomycin E biosynthesis in Streptomyces globisporus 1912.

The prx gene, which is highly homologous to putative proteinases, has been identified by sequencing in the vicinity of the biosynthetic gene cluster for landomycin E (LaE) biosynthesis (lnd) in Streptomyces globisporus 1912. The S. globisporus Pro6 gene, deficient in prx, produced fivefold less LaE than the parental strain.