Bacterial outer membrane channel for divalent metal ion acquisition
Bacterial outer membrane channel for divalent metal ion acquisition
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DOI：
10.1073/pnas.1110137108
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发表时间：
2011-09-13
影响因子：
11.1
通讯作者：
O'Brian, Mark R.
中科院分区：
文献类型：
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作者：
Hohle, Thomas H.;Franck, William L.;O'Brian, Mark R.
细菌膜功能的流行模型预测外膜对大多数小溶质是可渗透的，因为主要基于大小的孔具有有限的选择性。在这里，我们确定了mnoP在革兰氏阴性菌慢生根瘤菌作为一个基因与内膜锰离子转运蛋白基因mntH共调节。MnoP是在锰限制下特异性表达的外膜蛋白。MnoP作为通道促进Mn 2+（而不是Co 2+或Cu 2+）转运到重构的蛋白脂质体中。一个mnoP突变体是有缺陷的高亲和力Mn2+运输到细胞中，并有一个严重的生长表型下锰限制。我们认为外膜是二价金属离子的屏障，需要一个选择性的通道来满足细胞的营养需求。
The prevailing model of bacterial membrane function predicts that the outer membrane is permeable to most small solutes because of pores with limited selectivity based primarily on size. Here, we identified mnoP in the Gram-negative bacterium Bradyrhizobium japonicum as a gene coregulated with the inner membrane Mn2+ transporter gene mntH. MnoP is an outer membrane protein expressed specifically under manganese limitation. MnoP acts as a channel to facilitate the tranlocation of Mn2+, but not Co2+ or Cu2+, into reconstituted proteoliposomes. An mnoP mutant is defective in high-affinity Mn2+ transport into cells and has a severe growth phenotype under manganese limitation. We suggest that the outer membrane is a barrier to divalent metal ions that requires a selective channel to meet the nutritional needs of the cell.