7BNR

Crystal structure of a ParB Q52A mutant from Myxococcus xanthus bound to CTPyS

Summary for 7BNR

• Entry DOI: 10.2210/pdb7bnr/pdb
• Descriptor: ParB family protein, Cytosine 5'-[gamma-thio]triphosphate, GLYCEROL, ... (5 entities in total)
• Functional Keywords: dna-binding protein, ctp, myxococcus, dna-segregation, dna binding protein
• Biological source: Myxococcus xanthus (strain DK 1622)
• Total number of polymer chains: 2
• Total formula weight: 48010.96

Authors

Altegoer, F.,Bange, G. (deposition date: 2021-01-22, release date: 2021-09-08, Last modification date: 2024-01-31)

Primary citation

Osorio-Valeriano, M.,Altegoer, F.,Das, C.K.,Steinchen, W.,Panis, G.,Connolley, L.,Giacomelli, G.,Feddersen, H.,Corrales-Guerrero, L.,Giammarinaro, P.I.,Hanssmann, J.,Bramkamp, M.,Viollier, P.H.,Murray, S.,Schafer, L.V.,Bange, G.,Thanbichler, M.
The CTPase activity of ParB determines the size and dynamics of prokaryotic DNA partition complexes.
Mol.Cell, 81:3992-, 2021

PubMed Abstract: ParB-like CTPases mediate the segregation of bacterial chromosomes and low-copy number plasmids. They act as DNA-sliding clamps that are loaded at parS motifs in the centromere of target DNA molecules and spread laterally to form large nucleoprotein complexes serving as docking points for the DNA segregation machinery. Here, we solve crystal structures of ParB in the pre- and post-hydrolysis state and illuminate the catalytic mechanism of nucleotide hydrolysis. Moreover, we identify conformational changes that underlie the CTP- and parS-dependent closure of ParB clamps. The study of CTPase-deficient ParB variants reveals that CTP hydrolysis serves to limit the sliding time of ParB clamps and thus drives the establishment of a well-defined ParB diffusion gradient across the centromere whose dynamics are critical for DNA segregation. These findings clarify the role of the ParB CTPase cycle in partition complex assembly and function and thus advance our understanding of this prototypic CTP-dependent molecular switch.

PubMed: 34562373
DOI: 10.1016/j.molcel.2021.09.004

Experimental method

X-RAY DIFFRACTION (1.7 Å)