Open AccessSuppression of temperature‐sensitive sporulation mutation in the Bacillus subtilis sigA gene by rpoB mutation
Author(s) -
Nanamiya Hideaki,
Fugono Nobutake,
Asai Kei,
Doi Roy H,
Kawamura Fujio
Publication year - 2000
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2000.tb09388.x
Subject(s) - rpob , mutant , bacillus subtilis , sigma factor , biology , gene , microbiology and biotechnology , rna polymerase , mutation , transcription (linguistics) , suppressor mutation , gene expression , protein subunit , genetics , rna , bacteria , philosophy , 16s ribosomal rna , linguistics
We isolated a temperature‐sensitive sporulation defective mutant of the sigA gene, encoding a major sigma factor, σ A protein, in Bacillus subtilis , and designated it as sigA21 . The sigA21 mutation caused a single‐amino acid substitution, E314K, in region 4 of the σ A protein. In this mutant, expression of the spoIIG gene, whose transcription depends on both σ A and the phosphorylated Spo0A protein, Spo0A∼P, a major transcription factor during early stages of sporulation, was greatly reduced at 43°C. To obtain further information on the mechanism of σ A function during the early spore development, we isolated a spontaneous sporulation‐proficient suppressor mutant at 43°C. This extragenic suppressor mutation was mapped within the rpoB gene, encoding the β subunit of RNA polymerase, and was found to have a single‐amino acid substitution, A863G. In this mutant, the expression of the spoIIG is partially restored at 43°C.