High-Resolution Crystal Structure of the Subclass B3 Metallo-β-Lactamase BJP-1: Rational Basis for Substrate Specificity and Interaction with Sulfonamides
High-Resolution Crystal Structure of the Subclass B3 Metallo-β-Lactamase BJP-1: Rational Basis for Substrate Specificity and Interaction with Sulfonamides
复制标题
DOI：
10.1128/aac.00409-10
复制
发表时间：
2010-10-01
影响因子：
4.9
通讯作者：
Mangani, Stefano
中科院分区：
文献类型：
--
作者：
Docquier, Jean-Denis;Benvenuti, Manuela;Mangani, Stefano
金属- β -内酰胺酶（MBLs）是β -内酰胺类抗生素耐药的重要酶促因子，具有重要的结构和功能异质性。BJP-1是由日本慢生根瘤菌产生的B3类MBL决定因子，具有有趣的特性。与类弧菌cau1一样，BJP-1对β -内酰胺底物的识别能力总体较差，与其他MBLs相比，BJP-1表现出不同寻常的底物特征。为了了解这些性质的结构基础，在1.4-(A)过圆分辨率下获得了BJP-1的晶体结构。这揭示了活性位点环的构象和位置的显着差异，确定了一个相当狭窄的活性位点和一个独特的带有ph -31的n端螺旋的存在，其侧链结合在活性位点上，代表了β -内酰胺底物结合的障碍。为了探测磺胺类化合物（已知能抑制多种锌依赖性酶）与MBLs活性位点结合的潜力，我们还获得了BJP-1与4-硝基苯磺酰胺配合物的结构（在1.33-(A)过环分辨率下），从而揭示了这些分子在MBLs中的相互作用模式。有趣的是，磺胺结合导致ph -31的侧链从其疏水结合口袋中位移，在那里分子的苯环现在被发现。这些数据进一步强调了mbl所显示的结构多样性，同时也为这些酶的结构-功能关系提供了有趣的见解。更重要的是，我们首次提供了MBL与磺胺相互作用的结构观察，这可能为MBL抑制剂的设计提供了一个有趣的框架。
Metallo-beta-lactamases (MBLs) are important enzymatic factors in resistance to beta-lactam antibiotics that show important structural and functional heterogeneity. BJP-1 is a subclass B3 MBL determinant produced by Bradyrhizobium japonicum that exhibits interesting properties. BJP-1, like CAU-1 of Caulobacter vibrioides, overall poorly recognizes beta-lactam substrates and shows an unusual substrate profile compared to other MBLs. In order to understand the structural basis of these properties, the crystal structure of BJP-1 was obtained at 1.4-(A) over circle resolution. This revealed significant differences in the conformation and locations of the active-site loops, determining a rather narrow active site and the presence of a unique N-terminal helix bearing Phe-31, whose side chain binds in the active site and represents an obstacle for beta-lactam substrate binding. In order to probe the potential of sulfonamides (known to inhibit various zinc-dependent enzymes) to bind in the active sites of MBLs, the structure of BJP-1 in complex with 4-nitrobenzenesulfonamide was also obtained (at 1.33-(A) over circle resolution), thereby revealing the mode of interaction of these molecules in MBLs. Interestingly, sulfonamide binding resulted in the displacement of the side chain of Phe-31 from its hydrophobic binding pocket, where the benzene ring of the molecule is now found. These data further highlight the structural diversity shown by MBLs but also provide interesting insights in the structure-function relationships of these enzymes. More importantly, we provided the first structural observation of MBL interaction with sulfonamides, which might represent an interesting scaffold for the design of MBL inhibitors.