5H66

Crystal structure of the Bacillus subtilis SMC head domain complexed with the cognate ScpA C-terminal domain

Summary for 5H66

• Entry DOI: 10.2210/pdb5h66/pdb
• Related: 3W6J 3W6K 5H67 5H68 5H69
• Descriptor: Chromosome partition protein Smc, Segregation and condensation protein A, ... (4 entities in total)
• Functional Keywords: smc protein, dna binding protein-cell cycle complex, dna binding protein/cell cycle
• Biological source: Bacillus subtilis (strain 168) (Bacillus subtilis subsp. subtilis str. 168); More
• Total number of polymer chains: 3
• Total formula weight: 53273.82

Authors

Kamada, K.,Hirano, T. (deposition date: 2016-11-11, release date: 2017-03-15, Last modification date: 2023-11-08)

Primary citation

Kamada, K.,Su'etsugu, M.,Takada, H.,Miyata, M.,Hirano, T.
Overall Shapes of the SMC-ScpAB Complex Are Determined by Balance between Constraint and Relaxation of Its Structural Parts
Structure, 25:603-616.e4, 2017

PubMed Abstract: The SMC-ScpAB complex plays a crucial role in chromosome organization and segregation in many bacteria. It is composed of a V-shaped SMC dimer and an ScpAB subcomplex that bridges the two Structural Maintenance of Chromosomes (SMC) head domains. Despite its functional significance, the mechanistic details of SMC-ScpAB remain obscure. Here we provide evidence that ATP-dependent head-head engagement induces a lever movement of the SMC neck region, which might help to separate juxtaposed coiled-coil arms. Binding of the ScpA N-terminal domain (NTD) to the SMC neck region is negatively regulated by the ScpB C-terminal domain. Mutations in the ScpA NTD compromise this regulation and profoundly affect the overall shape of the complex. The SMC hinge domain is structurally relaxed when free from coiled-coil juxtaposition. Taken together, we propose that the structural parts of SMC-ScpAB are subjected to the balance between constraint and relaxation, cooperating to modulate dynamic conformational changes of the whole complex.

PubMed: 28286005
DOI: 10.1016/j.str.2017.02.008

Experimental method

X-RAY DIFFRACTION (1.82194772804 Å)