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. 2003 Nov 3;100(23):13603–13608. doi: 10.1073/pnas.2235180100

Fig. 1.

Fig. 1.

Protease-resistant SpxDD and its effect on srf-lacZ expression. (A) Amino acid sequence of Spx showing the location of the 2-Asp (DD) substitution at the C terminus. The CXXC motif is underlined. (B) Coomasssie-stained SDS-polyacrylamide gel of ClpXP proteolysis reactions containing either WT Spx protein or mutant SpxDD. Time of incubation is shown at the bottom. (C) Western blot analysis of whole-cell extracts obtained from cultures of the following strains: ORB4271 (amyE::pMMN521 [Pspank-hy-spx]), lanes marked spx; ORB4342 (amyE::pSN56 [Pspank-hy-spxDD]), lanes marked spxDD; ORB4343 (amyE::pSN56 rpoAcxs-1), lanes marked spxDD rpoAcxs-1. Marker (M) band is lysozyme (20.8 kDa). (D) Expression of transcriptional srf-lacZ over time in ORB4349 (srfA-lacZ [pMMN84] amyE::pSN56, circle) and ORB4353 (srfA-lacZ [pMMN84] amyE::pSN56, rpoAcxs-1, square) grown in DSM. The cultures were split at OD 600 = 0.5 at time 0 and grown in the absence (open symbols) or presence (filled symbols) of 1 mM IPTG. The x axis represents the time (h) of incubation after the addition of IPTG.