2XJ9: Dimer Structure Of The Bacterial Cell Division Regulator Mipz

Protein gradients play a central role in the spatial organization of cells, but the mechanisms of their formation are incompletely understood. This study analyzes the determinants responsible for establishing bipolar gradients of the ATPase MipZ, a key regulator of division site placement in Caulobacter crescentus. We have solved the crystal structure of MipZ in different nucleotide states, dissected its ATPase cycle, and investigated its interaction with FtsZ, ParB, and the nucleoid. Our results suggest that the polar ParB complexes locally stimulate the formation of ATP-bound MipZ dimers, which are then retained near the cell poles through association with chromosomal DNA. Due to their intrinsic ATPase activity, dimers eventually dissociate into freely diffusible monomers that undergo spontaneous nucleotide exchange and are recaptured by ParB. These findings clarify the molecular function of a conserved gradient-forming system and reveal mechanistic principles that might be commonly used to sustain protein gradients within cells.
PDB ID: 2XJ9Download
MMDB ID: 91507
PDB Deposition Date: 2010/7/2
Updated in MMDB: 2011/07
Experimental Method:
x-ray diffraction
Resolution: 2.8  Å
Source Organism:
Similar Structures:
Biological Unit for 2XJ9: dimeric; determined by author and by software (PISA)
Molecular Components in 2XJ9
Label Count Molecule
Proteins (2 molecules)
Mipz Synonym: Division Plane Positioning Atpase Mipz
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB