ALTERED PENICILLIN-BINDING COMPONENTS IN PENICILLIN-RESISTANT MUTANTS OF BACILLUS-SUBTILIS
ALTERED PENICILLIN-BINDING COMPONENTS IN PENICILLIN-RESISTANT MUTANTS OF BACILLUS-SUBTILIS
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DOI：
10.1073/pnas.73.6.1816
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发表时间：
1976-01-01
影响因子：
11.1
通讯作者：
STROMINGER, JL
中科院分区：
文献类型：
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作者：
BUCHANAN, CE;STROMINGER, JL
B的青霉素（氯唑青霉素）抗性突变体。以逐步的方式分离枯草芽孢杆菌，并检查每种中的5种青霉素结合组分（PBMC）以确定哪种蛋白质（如果有的话）对应于青霉素杀伤位点。PBCs III和V之前被排除作为可能的青霉素靶点。在目前的工作中，PBC IV在任何分离的耐药突变体中对氯唑西林的敏感性没有变化。PBC I直到第5步突变才发生变化，在第5步突变中不能通过青霉素结合检测到PBC I。由于PBC I不结合对该突变体致命的青霉素，因此它也不可能是致死靶标。PBC II在3个离散步骤中显示出对氯唑西林的耐药性增加，即，在突变体1、4和5中，伴随着其电泳迁移率的变化。PBC Ⅱ对青霉素G的敏感性变化不大。相应地，氯唑西林耐药突变体在体内对青霉素G的敏感性没有改变。在B中发现的5个PBMC中。对于枯草芽孢杆菌，PBC II是青霉素最可能的杀灭目标。
Penicillin- (cloxacillin-) resistant mutants of B. subtilis were isolated in a stepwise fashion and the 5 penicillin-binding components (PBCs) in each were examined to determine which of the proteins, if any, corresponds to the penicillin killing site. PBCs III and V were previously eliminated as the likely penicillin target. In the present work, PBC IV showed no change in sensitivity to cloxacillin in any of the resistant mutants isolated. PBC I did not change until the 5th-step mutant, in which it could not be detected by penicillin binding. Since PBC I did not bind penicillins that are lethal for this mutant, it also cannot be the lethal target. PBC II showed increased resistance to cloxacillin in 3 discrete steps, i.e., in mutants 1, 4 and 5, accompanied by changes in its electrophoretic mobility. The sensitivity of PBC II to penicillin G changed very little. Correspondingly, the cloxacillin-resistant mutants were unaltered in their sensitivity to penicillin G in vivo. Of the 5 PBCs found in B. subtilis, PBC II is the most likely target for killing by penicillins.