Löwe J
MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 2QH, UK.
J Struct Biol. 1998 Dec 15;124(2-3):235-43. doi: 10.1006/jsbi.1998.4041.
FtsZ is the polymer-forming protein of bacterial cell division. It is part of a ring in the middle of the dividing cell that is required for constriction of cell membrane and cell envelope to yield two daughter cells. FtsZ is a GTPase and is the only bacterial protein showing significant sequence homology to the eukaryotic tubulins. FtsZ can polymerize into tubes, sheets, and rings in vitro and is ubiquitous in eubacteria and archaea. Full-length FtsZ1 from Methanococcus jannaschii has been over expressed in Escherichia coli, employing the hyperthermophilic properties of the protein. Crystals grown from PEG400 and ethanol belong to spacegroup I213 with a = b = c = 159.1 A. Isomorphous replacement using one Hg derivative yielded a interpretable electron density map at 4 A resolution. The structure for residues 23-356 and one GDP has been refined to an Rfree of 0.28 (Rf = 0.20) at 2.8 A resolution. FtsZ consists of two domains with a connecting core helix. The N-terminal domain and the core helix contain all residues involved in nucleotide binding and resemble the fold of dinucleotide-binding proteins. The structures of tubulin and FtsZ show striking similarity; together with the functional similarities, this provides a strong indication that FtsZ is a true homolog of tubulin.
FtsZ是细菌细胞分裂过程中形成聚合物的蛋白质。它是正在分裂的细胞中部一个环的组成部分，该环是细胞膜和细胞包膜收缩以产生两个子细胞所必需的。FtsZ是一种GTP酶，是唯一与真核微管蛋白具有显著序列同源性的细菌蛋白。FtsZ在体外可聚合成管、片和环，在真细菌和古细菌中普遍存在。利用詹氏甲烷球菌的全长FtsZ1的嗜热特性，已在大肠杆菌中对其进行了过量表达。从PEG400和乙醇中生长的晶体属于空间群I213，a = b = c = 159.1埃。使用一种汞衍生物进行同晶置换，在4埃分辨率下得到了可解释的电子密度图。23 - 356位残基和一个GDP的结构在2.8埃分辨率下已精修至Rfree为0.28（Rf = 0.20）。FtsZ由两个结构域和一个连接核心螺旋组成。N端结构域和核心螺旋包含所有参与核苷酸结合的残基，并且类似于二核苷酸结合蛋白的折叠。微管蛋白和FtsZ的结构显示出惊人的相似性；连同功能上的相似性，这有力地表明FtsZ是微管蛋白的真正同源物。
