Insights into the molecular mechanism of Smc-based condensin by structural studies — ASN Events
  1. Schedule
  2. Session 10: Poster Session C
  3. Insights into the molecular mechanism of Smc-based condensin by structural studies

Insights into the molecular mechanism of Smc-based condensin by structural studies (#383)

Young-Min Soh 1 2 , Ho-Chul Shin 1 2 , Frank Bürmann 1 2 , Jérôme Basquin 1 2 , Mi-Jeong Kwak 1 2 , Han-Sol Lee 1 2 , Stephen Gruber 1 2 , Byung-Ha Oh* 1 2
  1. Department of Biological Sciences, KAIST, Korea
  2. Max Planck Research Group Chromosome Organization and Dynamics, Max Planck Institute of Biochemistry, Martinsried, Germany

Chromosomal condensation and segregation are essential processes of cell division. In most prokaryotic organisms, DNA is compacted into nucleoids mainly by the multi-subunit complex called Smc-ScpAB condensin that consists of a SMC (Structural maintenance of chromosome) protein and two non-SMC subunits ScpA and ScpB.

 Through the elucidation of three subcomplex structures of Smc-ScpAB, we were able to model the holocomplex which is a closed carabiner-like structure consisting of the homodimer of Smc which is asymmetrically bridged by the ScpA-(ScpB)2 complex. Condensins are known to entrap DNA fibers, suggesting that this carabiner-like structure has an opening and closing mechanism.

The model of the holocomplex revealed the structure of three interfaces between the subunits that could serve as a potential DNA entry gate. Other structural information and biochemical studies strongly suggest that one of the three interfaces opens and closes by an ATP-dependent manner.

  1. [Supported by National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2013-034955)]