Internalization of a thiazole-modified peptide in Sinorhizobium meliloti occurs by BacA-dependent and -independent mechanisms.
Internalization of a thiazole-modified peptide in Sinorhizobium meliloti occurs by BacA-dependent and -independent mechanisms.
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DOI：
10.1099/mic.0.039909-0
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发表时间：
2010-09
期刊：
影响因子：
1.5
通讯作者：
S. Wehmeier;M. Arnold;Victoria L. Marlow;Mustapha Aouida;Kamila K. Myka;Vivien Fletcher;Monica Benincasa;M. Scocchi;D. Ramotar;G. Ferguson
中科院分区：
文献类型：
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作者：
S. Wehmeier;M. Arnold;Victoria L. Marlow;Mustapha Aouida;Kamila K. Myka;Vivien Fletcher;Monica Benincasa;M. Scocchi;D. Ramotar;G. Ferguson
BacA 蛋白在苜蓿中华根瘤菌、流产布鲁氏菌和结核分枝杆菌在各自宿主体内的慢性细胞内感染中发挥关键作用。苜蓿中华根瘤菌、流产芽孢杆菌和结核分枝杆菌 BacA 缺陷突变体对噻唑修饰肽博莱霉素的耐药性增强。之前曾假设 BacA 参与博来霉素的摄取，但尚未经过实验验证。在本文中，我们表明 BacA 依赖性机制是苜蓿中华根瘤菌中博莱霉素内化的主要途径。我们还确定流产布鲁氏菌和苜蓿中华根瘤菌 BacA 蛋白是功能同源物，并且流产布鲁氏菌 BacA 蛋白参与博莱霉素和富含脯氨酸肽的摄取。我们的研究结果还提供了证据，表明苜蓿中华根瘤菌中存在第二种不依赖于 BacA 的博来霉素内化机制。我们确定博莱霉素摄取的 BacA 依赖性和非依赖性机制是能量依赖性的，与涉及运输系统的博莱霉素摄取的两种机制一致。
BacA proteins play key roles in the chronic intracellular infections of Sinorhizobium meliloti, Brucella abortus and Mycobacterium tuberculosis within their respective hosts. S. meliloti, B. abortus and M. tuberculosis BacA-deficient mutants have increased resistance to the thiazole-modified peptide bleomycin. BacA has been previously hypothesized, but not experimentally verified, to be involved in bleomycin uptake. In this paper, we show that a BacA-dependent mechanism is the major route of bleomycin internalization in S. meliloti. We also determined that the B. abortus and S. meliloti BacA proteins are functional homologues and that the B. abortus BacA protein is involved in the uptake of both bleomycin and proline-rich peptides. Our findings also provide evidence that there is a second, BacA-independent minor mechanism for bleomycin internalization in S. meliloti. We determined that the BacA-dependent and -independent mechanisms of bleomycin uptake are energy-dependent, consistent with both mechanisms of bleomycin uptake involving transport systems.