Nucleotide sequences of the sporulation gene spo0A and its mutant genes of Bacillus subtilis

Abstract

The nucleotide sequence of a 2375-base-pair DNA fragment, which contained the sporulation gene spoOA cloned from B. subtilis was determined. The sequence had only 1 long open reading frame consisting of 239 codons, which was found to corresond to the spo0A gene by comparing the nucleotide sequence of the wild-type gene with those of the mutant alleles. The calculated MW of the product of the wild-type spo0A gene was 26,500. A new mutation, sgi, which maps within the spo0A gene was also found. This mutation relieves the growth inhibition of the host cells caused by a multicopy plasmid carrying the spo0A gene. The mutations spo0A12, spo0C9V and sgi-1 were found to be an amber mutation at the 62nd codon, a missense at the 229th codon, and a frame-shift at the 223rd codon of the spo0A gene, respectively.