A tubulin-like, filament forming GTPase; the motor component of the type III plasmid partition system which ensures correct segregation of the pBc10987 plasmid (Probable). Binds GTP and forms filaments (PubMed:22847006). The filaments seed from a DNA centromere-like site (tubC)-TubR complex which extends to surround the TubZ filaments. Highly dynamic filaments grow at the plus end and depolymerize at the minus end, a process called treadmilling. TubR-tubC complexes track the depolymerizing minus end of the filament, probably pulling plasmid within the cell (By similarity). GTP + H2O = GDP + H(+) + phosphate Forms filaments. Filaments bind to TubR (PubMed:22847006). Binds to the TubR-tubC protein DNA complex (By similarity). Forms filaments. Expression is repressed by upstream TubR (at protein level). Probably part of the tubR-tubZ operon. Consists of two domains: a nucleotide-binding N-terminus that hydrolyzes GTP and a C-terminus domain necessary for polymerization. The domains are bridged by a long, central helix. The C-terminus is required for GTP hydrolysis in solution but not in crystals; it plays a role in filament assembly and in binding to TubR (PubMed:22847006). Interactions between the C-terminus and the following monomer drive polymerization (By similarity). Belongs to the FtsZ family. TubZ subfamily.