FIGURE 1.

AtrA is tightly regulated in S. roseosporus. (a) HPLC analysis of daptomycin fermentation levels in AtrAoe strain and WT. (b) pSET‐152 (atrAp‐atrA‐egfp) was used to complement ΔatrA strain. One microliter of YEME fermentation broth was taken at 24 h, diluted 10 times and observed under OLYMPUS BX51 microscope. Objective magnification is 20×. (c) qRT‐PCR was used to detect the changes of atrA transcription levels in WT and AtrAoe strain. The strains were fermented in YEME medium for 24, 48, 72, and 96 h to extract RNA, respectively. (d) AtrA (pET‐32a) was incubated with cell lysate of WT, which was fermented for 24 h, at 30°C in vitro. Samples after different incubation times were analyzed on a 10% SDS‐PAGE. Forty‐nine kilodaltons represented the molecular weight of AtrA. CL represented cell lysate.