FTSZ AND MYCOPLASMA PNEUMONIAE CELL DIVISION

大多数有壁原核生物的细胞分裂蛋白在无壁细菌肺炎支原体中都不存在，除了FtsZ的一个相当不同的同源物，它在其他生物的细胞分裂部位形成一个环。我们推测，如果肺炎支原体FtsZ在细胞质分裂中发挥作用，它必须独立于其他生物体中与FtsZ相关的其他活动，可能与一组不同的蛋白质有关；因此，肺炎支原体FtsZ必须具有新的特性。为了在分子水平上阐明肺炎支原体的细胞分裂机制，我们将在大肠杆菌中表达并纯化肺炎支原体的FtsZ同源基因。纯化的蛋白将被原位定位在支原体细胞中。此外，纯化的重组FtsZ蛋白将对核苷酸亲和力、核苷酸水解动力学及其聚合进行表征，以便能够将这些特性与其他生物的FtsZ同源物进行比较。最后，将寻找与肺炎支原体FtsZ相互作用的蛋白质。

Most of the cell division proteins of walled prokaryotes are absent in the wall-less bacterium Mycoplasma pneumoniae, with the exception of a considerably divergent homolog of FtsZ, which forms a ring at the cell division site in other organisms. We reason that if M. pneumoniae FtsZ functions in cytokinesis, it must do so independently of the other activities that are associated with FtsZ in other organisms, perhaps in association with a different set of proteins; M. pneumoniae FtsZ therefore must have novel properties. In order to begin to elucidate the mechanism of M. pneumoniae cell division at the molecular level, the FtsZ homolog of M. pneumoniae will be expressed in and purified from E coli. The purified protein will be localized in situ in mycoplasma cells. Furthermore, purified recombinant FtsZ protein will be characterized for nucleotide affinity, kinetics of nucleotide hydrolysis, and its polymerization, in order to enable comparison of these properties with those of the FtsZ homologs of other organisms. Finally, proteins that interact with M. pneumoniae FtsZ will be sought.