COPPER RESISTANCE IN PSEUDOMONAS-SYRINGAE MEDIATED BY PERIPLASMIC AND OUTER-MEMBRANE PROTEINS
COPPER RESISTANCE IN PSEUDOMONAS-SYRINGAE MEDIATED BY PERIPLASMIC AND OUTER-MEMBRANE PROTEINS
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DOI：
10.1073/pnas.88.20.8915
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发表时间：
1991-10-01
影响因子：
11.1
通讯作者：
COOKSEY, DA
中科院分区：
文献类型：
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作者：
CHA, JS;COOKSEY, DA
番茄假单胞菌致病变种的抗铜菌株在含铜培养基上积累铜并形成蓝色菌落。三个抗铜操纵子（cop）的蛋白质产物的特点是提供一个了解铜抗性机制及其与铜积累的关系。Cop蛋白CopA（72 kDa）、CopB（39 kDa）和CopC（12 kDa）仅在铜诱导下产生。CopA和CopC为周质蛋白，CopB为外膜蛋白。通过氨基末端肽测序确认CopA、CopB和CopC的前导肽序列。从菌株PT 23.2中纯化CopA、CopB和CopC，并测定其铜含量。一分子CopA结合10.9 +/-1.2个铜原子，一分子CopC结合0.6 +/-0.1个铜原子。Cop蛋白显然介导铜在细胞质外的螯合作为铜抗性机制。
Copper-resistant strains of Pseudomonas syringae pathovar tomato accumulate copper and develop blue colonies on copper-containing media. Three of the protein products of the copper-resistance operon (cop) were characterized to provide an understanding of the copper-resistance mechanism and its relationship to copper accumulation. The Cop proteins, CopA (72 kDa), CopB (39 kDa), and CopC (12 kDa), were produced only under copper induction. CopA and CopC were periplasmic proteins and CopB was an outer membrane protein. Leader peptide sequences of CopA, CopB, and CopC were confirmed by amino-terminal peptide sequencing. CopA, CopB, and CopC were purified from strain PT23.2, and their copper contents were determined. One molecule of CopA bound 10.9 +/- 1.2 atoms of copper and one molecule of CopC bound 0.6 +/- 0.1 atom of copper. The Cop proteins apparently mediate sequestration of copper outside of the cytoplasm as a copper-resistance mechanism.