| Type: | Family | Name: | Cell division protein FtsZ |
| Description: | This entry represents a group of FtsZ/tubulin GTPase domain containing proteins, including prokatyotic FtsZ and CetZ, and plant ARC3. FtsZ is a homologue of eukaryotic tubulin and is involved in the process of cell division, particularly in septum formation in bacteria []. CetZ co-exists with FtsZ in many archaea. Cetz does not affect cell division, instead, it is involved in cell shape control []. Arabidopsis chloroplast protein ARC3 (At1g75010) is a Z-ring accessory protein involved in the initiation of plastid division and division site placement [, ].In bacteria, FtsZ [, , ] is an essential cell division protein which appears to be involved in the initiation of this event. It assembles into a cytokinetic ring on the inner surface of the cytoplasmic membrane at the place where division will occur. The ring serves as a scaffold that is disassembled when septation is completed. FtsZ ring formation is initiated at a singlesite on one side of the bacterium and appears to grow bidirectionally. In Escherichia coli, MinCD , encoded by the MinB locus, form a complex which appears to block the formation of FtsZ rings at the cell poles, at the ancient mid cell division sites, whilst MinE, encoded at the same locus, specifically prevents the action of MinCD at mid cell.FtsZ is a GTP binding protein with a GTPase activity. It undergoes GTP-dependent polymerisation into filaments (or tubules) that seem to form a cytoskeleton involved in septum synthesis. The structure and the properties of FtsZ clearly provide it with the capacity for the cytoskeletal, perhaps motor role, necessary for "contraction" along the division plane. In addition, however, the FtsZ ring structure provides the framework for the recruitment or assembly of the ten or so membrane and cytoplasmic proteins, uniquely required for cell division in E. coli or Bacillus subtilis, some of which are required for biogenesis of the new hemispherical poles of the two daughter cells. FtsZ can polymerise into various structures, for example a single linear polymer of FtsZ monomers, called a protofilament. Protofilaments can associate laterally to form pairs (sometimes called thick filaments), bundles (ill-defined linear associations of multiple protofilaments) or thick filaments, sheets (parallel or anti-parallel two-dimensional associations of thick filaments) and tubes (anti-parallel associations of thick filaments in a circular fashion to form a tubular structure). In addition, small circles of FtsZ monomers (a short protofilament bent around to join itself, apparently head to tail) have been observed and termed mini-rings. FtsZ is a protein of about 400 residues which is well conserved across bacterial species and which is also present in the chloroplast of plants [] as well as in archaebacteria []. FtsZ shows structural similarity with eukaryotic tubulins. This similarity is probably both evolutionary andfunctionally significant. | Short Name: | Cell_div_FtsZ |
