The Bacillus subtilis sin gene, a regulator of alternate developmental processes, codes for a DNA-binding protein.
The sin gene of Bacillus subtilis encodes a dual-function regulatory protein, Sin, which is a negative as well as a positive regulator of alternate developmental processes that are induced at the end of vegetative growth in response to nutrient depletion. Sin has been purified to homogeneity by using a simple two-step procedure. It was found to bind to the developmentally regulated aprE (alkaline protease) gene at two sites in vitro. The stronger Sin-binding site (SBS-1) is located more than 200 bp upstream from the transcription start site. It is required for Sin repression of aprE expression in vivo, as strains bearing SBS-1 deletions were not affected by the sin gene. The second, weaker Sin-binding site lies on a DNA fragment that contains the aprE promoter. Results of DNase I, exonuclease III, and dimethyl sulfate footprinting analysis of SBS-1 suggested that Sin binding involves two adjacent binding sites which appear to contain two different partial dyad symmetries. An analysis of the predicted amino acid sequence of Sin revealed a potential leucine zipper protein dimerization motif which is flanked by two helix-turn-helix motifs that could be involved in recognizing two different dyad symmetries.
Gaur
N K
NK
Department of Microbiology, Public Health Research Institute, New York, New York.
Oppenheim
J
J
Smith
I
I
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics*; D005798:Genes, Bacterial; D005809:Genes, Regulator; D007700:Kinetics; D008969:Molecular Sequence Data; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011487:Protein Conformation; D012697:Serine Endopeptidases / Q000235:genetics*
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D012697:Serine Endopeptidases; C032923:microbial serine proteinases