Molecular cloning and expression of the sysB gene encoding an essential type I signal peptidase from Staphylococcus aureus
Molecular cloning and expression of the sysB gene encoding an essential type I signal peptidase from Staphylococcus aureus
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DOI：
10.1128/jb.178.19.5712-5718.1996
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发表时间：
1996-10-01
影响因子：
3.2
通讯作者：
Black, MT
中科院分区：
文献类型：
--
作者：
Cregg, KM;Wilding, EI;Black, MT
编码I型信号肽酶的基因spsB是从革兰氏阳性真细菌金黄色葡萄球菌中克隆出来的，该基因编码一个含有191个氨基酸残基的蛋白质，计算出的分子质量为21,692 Da。与已知I型信号肽酶的蛋白质序列比较表明，保存的氨基酸残基对于催化活性是重要的或必需的。该酶在大肠杆菌中已被高水平表达，并已被证明在体内对大肠杆菌前蛋白具有酶活性。将spsB基因转移到对复制温度敏感的质粒上的实验表明，spsB是一个必需基因。我们在spsB基因上游发现了一个开放阅读框，它编码一个I型信号肽酶同源物，包含174个氨基酸残基，计算出的分子质量为20146 Da，预计不具有催化活性。
The gene, spsB, encoding a type I signal peptidase has been cloned from the gram-positive eubacterium Staphylococcus aureus, The gene encodes a protein of 191 amino acid residues with a calculated molecular mass of 21,692 Da. Comparison of the protein sequence with those of known type I signal peptidases indicates conservation of amino acid residues known to be important or essential for catalytic activity, The enzyme has been expressed to high levels in Escherichia coli and has been demonstrated to possess enzymatic activity against E. coli preproteins in vivo, Experiments whereby the spsB gene was transferred to a plasmid that is temperature sensitive for replication indicate that spsB is an essential gene. We identified an open reading frame immediately upstream of the spsB gene which encodes a type I signal peptidase homolog of 174 amino acid residues with a calculated molecular mass of 20,146 Da that is predicted to be devoid of catalytic activity.