Hayashi I, Oyama T, Morikawa K
Department of Structural Biology, Biomolecular Engineering Research Institute, 6-2-3 Furuedai, Suita-City, Osaka 565-0874, Japan.
EMBO J. 2001 Apr 17;20(8):1819-28. doi: 10.1093/emboj/20.8.1819.
Proper placement of the bacterial cell division site requires the site-specific inactivation of other potential division sites. In Escherichia coli, selection of the correct mid-cell site is mediated by the MinC, MinD and MinE proteins. To clarify the functional role of the bacterial cell division inhibitor MinD, which is a membrane-associated ATPase that works as an activator of MinC, we determined the crystal structure of a Pyrococcus furiosus MinD homologue complexed with a substrate analogue, AMPPCP, and with the product ADP at resolutions of 2.7 and 2.0 A, respectively. The structure reveals general similarities to the nitrogenase iron protein, the H-Ras p21 and the RecA-like ATPase domain. Alanine scanning mutational analyses of E.coli MinD were also performed in vivo. The results suggest that the residues around the ATP-binding site are required for the direct interaction with MinC, and that ATP binding and hydrolysis play a role as a molecular switch to control the mechanisms of MinCDE-dependent bacterial cell division.
细菌细胞分裂位点的正确定位需要使其他潜在分裂位点在特定位置失活。在大肠杆菌中，正确的细胞中部位点的选择由MinC、MinD和MinE蛋白介导。为阐明细菌细胞分裂抑制剂MinD的功能作用，MinD是一种膜相关ATP酶，作为MinC的激活剂起作用，我们分别以2.7 Å和2.0 Å的分辨率测定了与底物类似物AMPPCP以及产物ADP复合的嗜热栖热菌MinD同源物的晶体结构。该结构显示出与固氮酶铁蛋白、H-Ras p21以及RecA样ATP酶结构域的总体相似性。还在体内对大肠杆菌MinD进行了丙氨酸扫描突变分析。结果表明，ATP结合位点周围的残基是与MinC直接相互作用所必需的，并且ATP结合和水解作为分子开关在控制MinCDE依赖性细菌细胞分裂机制中发挥作用。
