Effects of amino acid substitutions in the promoter -10 binding region of the sigma A factor on growth of Bacillus subtilis.
On the bases of structural and functional information about the Bacillus subtilis sigma A protein and the techniques of site-directed mutagenesis, we constructed a B. subtilis sigA mutant (DB1005) which grows normally at 37 degrees C but is sensitive to higher temperatures. DNA sequencing analyses revealed that DB1005 has Ile-198-->Ala and Ile-202-->Ala amino acid substitutions in the alpha-helix of the 2.4 region of the sigma A protein. Western blotting (immunoblotting) revealed that this mutant sigma A protein is stable at both 37 and 49 degrees C. These results suggest that Ile-198 and Ile-202 separately or in combination are critical for the sigma A protein to be functional at the restrictive temperature.
Chang
B Y
BY
Agricultural Biotechnology Laboratories, National Chung-Hsin University, Taichung, Taiwan, Republic of China.
Doi
R H
RH
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics / Q000254:growth & development*; D001483:Base Sequence; D001665:Binding Sites; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic; D011487:Protein Conformation; D012808:Sigma Factor / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D013329:Structure-Activity Relationship; D014169:Transformation, Bacterial
D012808:Sigma Factor