Molecular Architecture of Smc Proteins and the Yeast Cohesin ComplexHaering, C., Lowe, J., Hochwagen, A., Nasmyth, K.
(2002) Mol Cell 9: 773
- PubMed: 11983169
- DOI: https://doi.org/10.1016/s1097-2765(02)00515-4
- Primary Citation of Related Structures:
1GXJ, 1GXK, 1GXL
- PubMed Abstract:
Sister chromatids are held together by the multisubunit cohesin complex, which contains two SMC (Smc1 and Smc3) and two non-SMC (Scc1 and Scc3) proteins. The crystal structure of a bacterial SMC "hinge" region along with EM studies and biochemical experiments on yeast Smc1 and Smc3 proteins show that SMC protamers fold up individually into rod-shaped molecules. A 45 nm long intramolecular coiled coil separates the hinge region from the ATPase-containing "head" domain. Smc1 and Smc3 bind to each other via heterotypic interactions between their hinges to form a V-shaped heterodimer. The two heads of the V-shaped dimer are connected by different ends of the cleavable Scc1 subunit. Cohesin therefore forms a large proteinaceous loop within which sister chromatids might be entrapped after DNA replication.
Research Institute of Molecular Pathology, Dr. Bohr Gasse 7, A-1030 Vienna, Austria.