Osmotic regulation of the Streptomyces lividans thiostrepton-inducible promoter, ptipA.

摘要: Transcriptional activation of the thiostrepton-inducible promoter, ptipA, in Streptomyces lividans is mediated by TipAL. This transcriptional activator belongs to MerR/SoxR family that characteristically binds an operator sequence located between -10 and -35 hexamers normally occupied RNA polymerase. As for Escherichia coli merT ptipA are separated a long 19 bp spacer hence topological transition DNA likely be requisite alignment with Growth conditions could facilitate this conformational change were investigated using fusions reporter genes. Adjustment growth medium osmolarity led increased prolonged TipAL-dependent expression, both without inducer, thiostrepton. These effects correlated increases negative supercoiling. Moreover, inability induce promoter thiostrepton strain TK64 was corrected increasing concentration osmolyte, compensating apparent reduced level supercoiling strain. Prolonging time tipA wild-type manipulating revealed mycelial autolysis induced 4-d-old cultures.