Accumulation of S-adenosylmethionine induced oligopeptide transporters including BldK to regulate differentiation events in Streptomyces coelicolor M145.

S-Adenosylmethionine (SAM), the major methyl donor in diverse biological processes, was recently found to be involved in the regulation of differentiation in streptomycetes. Exogenous SAM, in a quantity as low as 2muM, enhanced antibiotic production and inhibited morphological development of Streptomyces coelicolor M145. Total protein profiling of S. coelicolor M145 revealed that SAM enhanced the expression of oligopeptide-binding components related to ABC transporters that included BldK, a well-known regulatory factor in S. coelicolor differentiation. A radiolabeled SAM feeding experiment verified that exogenous SAM can be imported into the cell, which is under the control of the bld cascade. This study substantiated that BldK serves as a transducer of the SAM signal and uncovered the possible role of oligopeptide import in the regulation of Streptomyces differentiation, particularly in relation to SAM.