5H69

Crystal structure of an asymmetric dimer of the Geobacillus stearothermophilus SMC hinge domain

Summary for 5H69

• Entry DOI: 10.2210/pdb5h69/pdb
• Related: 3W6J 3W6K 5H66 5H67 5H68
• Descriptor: Chromosome partition protein Smc (2 entities in total)
• Functional Keywords: smc protein, dna binding protein, cell cycle
• Biological source: Geobacillus stearothermophilus 10
• Total number of polymer chains: 2
• Total formula weight: 57934.03

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 (2.20040022156 Å)