FIG. 4.

SP regulation of RpoS depends on the rpoS ribosome-binding sequence and Fis. (A) The 24 nt preceding the rpoS initiation codon were replaced by the depicted lacZ RBS in the native rpoS context. (B) The SP induction ratio of the katE-lac reporter fusion was determined in a wild type and a fis mutant background (rpoS RBS). SP induction of katE-lac was also determined in the context depicted in panel A, with or without a fis deletion (lacZ RBS). (C) Western analysis of RpoS protein during exponential growth in the indicated backgrounds. Strain numbers for the constructs (reading from top to bottom in panel B) are TE9145, TE9302, TE9284, and TE9303.