NUCLEOTIDE-SEQUENCE OF BACILLUS-SUBTILIS-DNAB - A GENE ESSENTIAL FOR DNA-REPLICATION INITIATION AND MEMBRANE ATTACHMENT
NUCLEOTIDE-SEQUENCE OF BACILLUS-SUBTILIS-DNAB - A GENE ESSENTIAL FOR DNA-REPLICATION INITIATION AND MEMBRANE ATTACHMENT
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DOI：
10.1073/pnas.84.3.653
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发表时间：
1987-02-01
影响因子：
11.1
通讯作者：
SUEOKA, N
中科院分区：
文献类型：
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作者：
HOSHINO, T;MCKENZIE, T;SUEOKA, N
测定了枯草芽孢杆菌dnaB基因及其侧翼区域的全核苷酸序列。dna基因是染色体和质粒pUB110起始区复制起始和膜附着所必需的。已知dna突变体有两种不同的类型（dna abi和dna ii）；dna是染色体和pUB110复制所必需的，而dna仅是染色体复制所必需的。核苷酸序列分析表明，dna - i和dna - ii是dna - b基因的两个功能域。两个突变体的突变位点，分别属于dnaBI和dnaBII，也被确定为氨基酸的取代。从核苷酸序列推断出的推定DnaB蛋白由472个氨基酸（55 kDa）组成，无半胱氨酸残基。在体外转录-翻译系统中产生的55-kDa多肽被[35S]蛋氨酸标记，而不被[35S]半胱氨酸标记。DnaB蛋白在其n端区域有一个由20个氨基酸组成的高度疏水序列，一个可能的DNA结合位点和两个可能的ATP结合位点。DNA abi结构域位于DNA结合位点和其中一个ATP结合位点之间；dnaBII结构域靠近另一个ATP结合位点。与大肠杆菌其他dna基因的氨基酸序列比较，发现“dnaB蛋白”的氨基酸序列无同源性，提示枯草芽孢杆菌的dnaB基因可能与大肠杆菌中迄今未发现的基因类似。
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.