5h66 | pdb_00005h66
Crystal structure of the Bacillus subtilis SMC head domain complexed with the cognate ScpA C-terminal domain
Structural highlights
Function[SMC_BACSU] Required for chromosome condensation and partitioning.[1] [2] [SCPA_BACSU] Participates in chromosomal partition during cell division. May act via the formation of a condensin-like complex containing Smc and ScpB that pull DNA away from mid-cell into both cell halves.[HAMAP-Rule:MF_01805] Publication Abstract from PubMedThe 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. Overall Shapes of the SMC-ScpAB Complex Are Determined by Balance between Constraint and Relaxation of Its Structural Parts.,Kamada K, Su'etsugu M, Takada H, Miyata M, Hirano T Structure. 2017 Apr 4;25(4):603-616.e4. doi: 10.1016/j.str.2017.02.008. Epub 2017, Mar 9. PMID:28286005[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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