A22 disrupts the bacterial actin cytoskeleton by directly binding and inducing a low-affinity state in MreB.
A22 disrupts the bacterial actin cytoskeleton by directly binding and inducing a low-affinity state in MreB.
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DOI：
10.1021/bi900014d
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发表时间：
2009-06-09
期刊：
影响因子：
2.9
通讯作者：
Amann, K. J.
中科院分区：
文献类型：
--
作者：
Bean, G. J.;Fllckinger, S. T.;Westler, W. M.;McCully, M. E.;Sept, D.;Weibel, D. B.;Amann, K. J.
S-（3,4-二氯苯基）异硫脲（A22）破坏细菌的肌动蛋白细胞骨架，导致形态缺陷和染色体分离。以往的研究表明，肌动蛋白同源物MreB本身是A22的靶标，但没有直接观察到A22与MreB的结合，也没有对其作用方式的机制解释。我们目前表明，A22在其核苷酸结合口袋中以至少微摩尔的亲和力与MreB结合，这种方式与同时结合ATP的方式在空间上不相容。在ATP存在的情况下，A22对体外MreB聚合的时间和程度都有负面影响。A22可防止MreB组装成长而坚硬的聚合物，这是通过荧光显微镜和沉淀试验确定的。A22将atp结合MreB组装的临界浓度从500 nM提高到约2000 nM。因此，我们得出结论，A22是ATP与MreB结合的竞争性抑制剂。a22结合的MreB具有聚合能力，但具有更接近adp结合状态的组装性质。由于MreB的细胞浓度在低微摩尔范围内，这一机制解释了A22在细菌细胞中大量分解肌动蛋白细胞骨架的能力。它也代表了细胞骨架药物的一种新的作用模式，以及细菌细胞骨架的小分子抑制剂与其靶标之间相互作用的第一个生化表征。
S-(3,4-dichlorobenzyl)isothiourea (A22) disrupts the actin cytoskeleton of bacteria, causing defects of morphology and chromosome segregation. Previous studies have suggested that the actin homolog MreB itself is the target of A22, but there has been no direct observation of A22 binding to MreB and no mechanistic explanation of its mode of action. We presently show that A22 binds MreB with at least micromolar affinity in its nucleotide binding pocket in a manner that is sterically incompatible with simultaneous ATP binding. A22 negatively affects both the timecourse and extent of MreB polymerization in vitro in the presence of ATP. A22 prevents MreB assembly into long, rigid polymers, as determined by both fluorescence microscopy and sedimentation assays. A22 increases the critical concentration of ATP-bound MreB assembly from 500 nM to approximately 2000 nM. We therefore conclude that A22 is a competitive inhibitor of ATP binding to MreB. A22-bound MreB is capable of polymerization, but with assembly properties that more closely resemble those of the ADP-bound state. Because the cellular concentration of MreB is in the low micromolar range, this mechanism explains the ability of A22 to largely disassemble the actin cytoskeleton in bacterial cells. It also represents a novel mode of action for a cytoskeletal drug and the first biochemical characterization of the interaction between a small molecule inhibitor of the bacterial cytoskeleton and its target.
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影响因子：
3.6
作者：
Divakaruni, Arun V.;Baida, Cyril;Gober, James W.
通讯作者：
Gober, James W.
DOI：
10.1073/pnas.0507708102
发表时间：
2005-12-20
影响因子：
11.1
作者：
Dye, NA;Pincus, Z;Gitai, Z
通讯作者：
Gitai, Z
影响因子：
11.4
作者：
Kruse, T;Moller-Jensen, J;Gerdes, K
通讯作者：
Gerdes, K
影响因子：
21.3
作者：
Morton, WM;Ayscough, KR;McLaughlin, PJ
通讯作者：
McLaughlin, PJ
DOI：
10.1073/pnas.0402638101
发表时间：
2004-06-08
影响因子：
11.1
作者：
Gitai, Z;Dye, N;Shapiro, L
通讯作者：
Shapiro, L