Cadmium resistance from Staphylococcus aureus plasmid pI258 cadA gene results from a cadmium-efflux ATPase.
Cadmium resistance from Staphylococcus aureus plasmid pI258 cadA gene results from a cadmium-efflux ATPase.
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DOI：
10.1073/pnas.86.10.3544
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发表时间：
1989-05
影响因子：
11.1
通讯作者：
G. Nucifora;L. Chu;T. K. Misra;S. Silver
中科院分区：
文献类型：
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作者：
G. Nucifora;L. Chu;T. K. Misra;S. Silver
由金黄色葡萄球菌质粒pI 258的cadA决定簇指定的镉抗性是由镉外排系统的功能引起的。在含有cadA决定簇的DNA片段的核苷酸序列中，鉴定出两个开放阅读框。较大的一个，对应于预测的727个氨基酸残基的多肽，对于镉抗性的表达是必要且足够的。与已知蛋白质序列的CadA氨基酸序列的比较表明，CadA是E1 E2阳离子转运ATP酶的成员，类似于革兰氏阳性菌和革兰氏阴性菌的K+摄取ATP酶。该序列与其他E1 E2型ATP酶的同源性较低，但与其他E1 E2型ATP酶的同源性显著，包括真核微生物的H+-流出ATP酶和动物的Ca 2 +-和Na+/K+-ATP酶。基因中间的移码突变破坏了Cd 2+抗性表型。一个详细的模型，推定的CadA ATP酶的同源性的基础上，其他E1 E2 ATP酶的介绍和讨论。
Cadmium resistance specified by the cadA determinant of Staphylococcus aureus plasmid pI258 results from the functioning of a cadmium-efflux system. In the nucleotide sequence of the DNA fragment containing the cadA determinant, two open reading frames were identified. The larger one, corresponding to a predicted polypeptide of 727 amino acid residues, is necessary and sufficient for expression of cadmium resistance. Comparison of the CadA amino acid sequence with known protein sequences suggested that CadA is a member of the E1E2 cation-translocating ATPases, similar to the K+-uptake ATPases of Gram-positive and Gram-negative bacteria. The sequence homology is lower but significant with other E1E2-type ATPases, including the H+-efflux ATPases of eukaryotic microbes and the Ca2+- and Na+/K+-ATPases of animals. A frame-shift mutation in the middle of the gene destroys the Cd2+-resistance phenotype. A detailed model for the putative CadA ATPase based on homologies to other E1E2 ATPases is presented and discussed.