Molecular characterization of the copper transport system in Staphylococcus aureus
Molecular characterization of the copper transport system in Staphylococcus aureus
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DOI：
10.1099/mic.0.2007/009860-0
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发表时间：
2007-12-01
期刊：
影响因子：
2.8
通讯作者：
Jayaswal, Radheshyam K.
中科院分区：
文献类型：
--
作者：
Sitthisak, Sutthirat;Knutsson, Lawrence;Jayaswal, Radheshyam K.
金黄色葡萄球菌CopA基因编码一个可能的铜转运P型ATPase，下游的CopZ基因编码一个铜伴侣。基因组数据库分析表明，这些铜转运基因在金黄色葡萄球菌中高度保守。铜离子可诱导CopA和CopZ的表达，铁离子和铅离子也可在一定程度上诱导其表达。含有部分缺失的CopA基因的突变菌株对铜、铁和铅离子的敏感性高于亲本菌株。铜敏感的表型是由于细胞内铜的积累，因此COPA产物参与了铜离子的输出。突变株对金属敏感的表型在反式上得到了2.7kbP的COPA DNA的补充。我们克隆并高效表达了COPA和COPZ的金属结合域，并通过定点突变证明了COPA中CXXC金属结合基序中的半胱氨酸残基参与了铜的结合，从而在金黄色葡萄球菌的铜转运中发挥了重要作用。
The Staphylococcus aureus copA gene codes for a putative copper-translocating P-type ATPase and the downstream copZ gene codes for a copper chaperone. Genome database analyses demonstrate that these copper transport genes are highly conserved in S. aureus. The expression of copA and copZ was inducible by copper and to some extent by ferric and lead ions. A mutant strain containing a partially deleted copA gene was more sensitive than the parent strain to copper, ferric and lead ions. The copper-sensitive phenotype was due to the accumulation of intracellular copper and thus the copA product is involved in the export of copper ions. The metal-sensitive phenotype of the mutant was complemented in trans by a 2.7 kbp DNA containing copA. We have cloned and overexpressed the metal-binding domains of CopA and CopZ and have shown by site-directed mutagenesis that the cysteine residues in the CXXC metal-binding motif in CopA are involved in copper binding and thus play an important role in copper transport in S. aureus.