3j4t

Helical model of TubZ-Bt two-stranded filamentHelical model of TubZ-Bt two-stranded filament

3j4t, resolution 10.80Å Show:Asymmetric Unit Biological Assembly Structural highlights 3j4t is a 1 chain structure with sequence from Bacillus thuringiensis serovar israelensis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 10.8Å Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function TUBZ_BACTI A tubulin-like, filament forming GTPase; the motor component of the type III plasmid partition system which ensures correct segregation of the pBtoxis plasmid. Filaments may seed from the centromere-like site (tubC) when bound by DNA-binding protein TubR; the tubC-TubR complex stabilizes the TubZ filament. 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 (PubMed:20534443, PubMed:23010931, PubMed:25825718). Required for pBtoxis plasmid replication/partition (PubMed:16936050, PubMed:17873046). Binds the TubR-tubC complex; GTP is not required for binding to TubR-tubC. TubZ alone does not bind DNA (PubMed:17873046, PubMed:20534443, PubMed:25825718). Has a high GTPase activity in the presence of Mg(2+); in the presence of GTP assembles into dynamic filaments which upon polymerization bind almost exclusively GDP. Filament formation is cooperative, requiring a critical concentration. Formation occurs very quickly and is followed by disassembly as GTP is consumed (PubMed:18198178).