Crystal Structures of Penicillin-Binding Protein 3 (PBP3) from Methicillin-Resistant Staphylococcus aureus in the Apo and Cefotaxime-Bound Forms
Crystal Structures of Penicillin-Binding Protein 3 (PBP3) from Methicillin-Resistant Staphylococcus aureus in the Apo and Cefotaxime-Bound Forms
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DOI：
10.1016/j.jmb.2012.07.012
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发表时间：
2012-10-26
影响因子：
5.6
通讯作者：
Park, Sam-Yong
中科院分区：
文献类型：
--
作者：
Yoshida, Hisashi;Kawai, Fumihiro;Park, Sam-Yong
金黄色葡萄球菌是一种广泛存在的革兰氏阳性条件致病菌，耐甲氧西林金黄色葡萄球菌(MRSA)的临床治疗尤为困难。我们从MRSA中解析了青霉素结合蛋白(PBP)3(PBP3)的两种晶体结构，即apo形式和与β-内酰胺类抗生素头孢噻肟的络合物，并用电喷雾质谱仪测定了其对多种青霉素衍生物的敏感性。PBP3是一种B类PBP，具有N端非青霉素结合区(有时称为二聚结构域)和C端转肽酶结构域。与其他B类PBP的早期模型和新的、更大的N-结构域相比，该模型显示了其两个结构域的不同取向。与“二聚结构域”的命名一致，N-末端区域与相邻分子形成明显的紧密相互作用，通过晶体结构中的2个对称轴联系在一起。PISA服务器预测这种二聚体形式在溶液中高度稳定，但质谱学和分析超速离心法提供了明确的证据，证明该蛋白质在溶液中是单体。(C)2012爱思唯尔有限公司。保留所有权利。
Staphylococcus aureus is a widespread Gram-positive opportunistic pathogen, and a methicillin-resistant form (MRSA) is particularly difficult to treat clinically. We have solved two crystal structures of penicillin-binding protein (PBP) 3 (PBP3) from MRSA, the apo form and a complex with the beta-lactam antibiotic cefotaxime, and used electrospray mass spectrometry to measure its sensitivity to a variety of penicillin derivatives. PBP3 is a class B PBP, possessing an N-terminal non-penicillin-binding domain, sometimes called a dimerization domain, and a C-terminal transpeptidase domain. The model shows a different orientation of its two domains compared to earlier models of other class B PBPs and a novel, larger N-domain. Consistent with the nomenclature of "dimerization domain", the N-terminal region forms an apparently tight interaction with a neighboring molecule related by a 2-fold symmetry axis in the crystal structure. This dimer form is predicted to be highly stable in solution by the PISA server, but Mass spectrometry and analytical ultracentrifugation provide unequivocal evidence that the protein is a monomer in solution. (C) 2012 Elsevier Ltd. All rights reserved.