Transformation of the Methylotrophic Actinomycete Amycolatopis methanolica with Plasmid DNA: Stimulatory Effect of a pMEA300-Encoded Gene

Amycolatopsis methanolica contains a 13.29-kb plasmid (pMEA300) present both in the free state and integrated at a unique genomic location. A pMEA300-free derivative (strain WV1) was selected, allowing further analysis of pMEA300-encoded functions. Whole cells of strain WV1 could be transformed at high frequencies (approximately 10^6 transformants per microgram of plasmid DNA) with both circular and linear plasmid DNA, provided that the pMEA300-encoded stf (stimulation of transformation frequency) gene was present. stf would encode a putative protein of 373 amino acids with Mr 40,201, resembling putative regulatory proteins involved in sporulation of Streptomyces griseus and Streptomyces coelicolor.

A plasmid from the methylotrophic actinomycete Amycolatopsis methanolica capable of site-specific integration.

Amycolatopsis methanolica contains a 13.3-kb plasmid (pMEA300) which is present both in the free state and integrated at a unique genomic location. A 2.1-kb pMEA300 DNA fragment was sequenced, revealing the putative attP site and two open reading frames, xis and int, showing similarity to genes encoding excisionases and integrases, respectively