Study of Streptomyces Ghanaensis Atcc14672 Genes Ssfg_03627 and Ssfg_01411 Encoding Putative Membrane Proteins

Abstract

Streptomyces ghanaensis ATCC14672 produces moenomycin A, a potent phosphoglycolipid antibiotic that targets bacterial peptidoglycan glycosyltransferases (PGTs). The genetic and biochemical aspects of assembly of moenomycin molecule is well understood. Yet, it remains unknown how moenomycins are transported from the cell into an environment, and whether the active export of moenomycin might be important for resistance of producer to its own potentially toxic secondary metabolite. There is overall structural and functional similarity between moenomycin and Lipid II an essential precursor to peptidoglycan (common lipid-glycoside scaffold, both bind PGTs). We hypothesized that proteins responsible for Lipid II transport across the S. ghanaensis membrane, analogous to MurJ in Escherichia coli, could also be involved in moenomycin export. In this work we describe initial genetic characterization of two MurJ-like S. ghanaensis ATCC14672 genes, SSFG_03627 and SSFG_01411. We revealed that gene SSFG_03627 is essential and could be deleted from S. ghanaensis ATCC14672 genome only in presence (in trans) of the second SSFG_03627 gene copy. Attempts to complement murJ-deficient E. coli NR1154 strain with either SSFG_03627 or SSFG_01411 gene were unsuccessful. Manipulations of SSFG_03627 gene copy number had complex influences on moenomycin production in S. ghanaensis ATCC14672.