2XKB

Crystal structure of GDP-form protofilaments of Bacillus thuringiensis serovar israelensis TubZ

Summary for 2XKB

• Entry DOI: 10.2210/pdb2xkb/pdb
• Related: 2XKA
• Descriptor: FTSZ/TUBULIN-RELATED PROTEIN, GUANOSINE-5'-DIPHOSPHATE, MAGNESIUM ION (3 entities in total)
• Functional Keywords: structural protein, motor protein, cytoskeleton, cytomotive, dna segregation, microtubule, pbtoxis, pbt156, repx, tubr
• Biological source: BACILLUS THURINGIENSIS
• Total number of polymer chains: 12
• Total formula weight: 582879.45

Authors

Aylett, C.H.S.,Lowe, J. (deposition date: 2010-07-07, release date: 2010-11-10, Last modification date: 2023-12-20)

Primary citation

Aylett, C.H.,Wang, Q.,Michie, K.A.,Amos, L.A.,Lowe, J.
Filament Structure of Bacterial Tubulin Homologue Tubz.
Proc.Natl.Acad.Sci.USA, 107:19766-, 2010

PubMed Abstract: Low copy number plasmids often depend on accurate partitioning systems for their continued survival. Generally, such systems consist of a centromere-like region of DNA, a DNA-binding adaptor, and a polymerizing cytomotive filament. Together these components drive newly replicated plasmids to opposite ends of the dividing cell. The Bacillus thuringiensis plasmid pBToxis relies on a filament of the tubulin/FtsZ-like protein TubZ for its segregation. By combining crystallography and electron microscopy, we have determined the structure of this filament. We explain how GTP hydrolysis weakens the subunit-subunit contact and also shed light on the partitioning of the plasmid-adaptor complex. The double helical superstructure of TubZ filaments is unusual for tubulin-like proteins. Filaments of ParM, the actin-like partitioning protein, are also double helical. We suggest that convergent evolution shapes these different types of cytomotive filaments toward a general mechanism for plasmid separation.

PubMed: 20974911
DOI: 10.1073/PNAS.1010176107

Experimental method

X-RAY DIFFRACTION (3 Å)