Nucleotide sequence of Bacillus subtilis dnaB: a gene essential for DNA replication initiation and membrane attachment.
AUTOR(ES)
Hoshino, T
RESUMO
The complete nucleotide sequence of the Bacillus subtilis dnaB gene and its flanking regions was determined. The dnaB gene is essential for both replication initiation and membrane attachment of the origin region of the chromosome and plasmid pUB110. It has been known that there are two different classes (dnaBI and dnaBII) in the dnaB mutants; dnaBI is essential for both chromosome and pUB110 replication, whereas dnaBII is necessary only for chromosome replication. The nucleotide sequence revealed that dnaBI and dnaBII are two functional domains in the single dnaB gene. The mutation sites of two mutants, belonging to dnaBI and dnaBII, respectively, were also determined as substitutions of amino acids. The putative DnaB protein deduced from nucleotide sequence consists of 472 amino acids (55 kDa) with no cysteine residue. A 55-kDa polypeptide produced in an in vitro transcription-translation system was labeled with [35S]methionine but not with [35S]cysteine. The DnaB protein has a highly hydrophobic sequence of 20 amino acids in its N-terminal region, a possible DNA binding site, and two possible ATP binding sites. The dnaBI domain is between the DNA binding site and one of the ATP binding sites; the dnaBII domain is close to the other ATP binding site. Comparison of the amino acid sequence between the "dnaB protein" and those of other dna genes of Escherichia coli showed no homology, suggesting that the dnaB gene of B. subtilis may be analogous to a hitherto undiscovered gene in E. coli.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=304273Documentos Relacionados
- Nucleotide sequence and organization of dnaB gene and neighbouring genes on the Bacillus subtilis chromosome.
- Effects of temperature-sensitive variants of the Bacillus subtilis dnaB gene on the replication of a low-copy-number plasmid.
- DNA-membrane association is necessary for initiation of chromosomal and plasmid replication in Bacillus subtilis.
- Sequence of the dnaB gene of Salmonella typhimurium.
- Escherichia coli dnaB mutant defective in DNA initiation: isolation and properties of the dnaB protein.