Structure of the Pds5-Scc1 Complex and Implications for Cohesin Function.

Area of Science:

• Molecular biology
• Cell biology
• Genetics

Background:

• Sister chromatid cohesion is vital for accurate genome segregation during cell division.
• The cohesin complex, along with accessory factors like Pds5, regulates chromosome cohesion.
• Pds5 plays a dual role in both facilitating and releasing cohesin from chromatin.

Purpose of the Study:

• To elucidate the molecular basis of Pds5 function in regulating cohesin.
• To determine the structural interaction between Pds5 and Scc1.

Main Methods:

• X-ray crystallography to obtain the structure of the Pds5-Scc1 complex.
• Biochemical and cellular assays to assess the functional importance of the Pds5-Scc1 interface.

Main Results:

• The crystal structure reveals Pds5 as an elongated HEAT repeat that binds Scc1 via a conserved surface.
• The Pds5-Scc1 interface is crucial for Pds5 recruitment to cohesin.
• Disruption of the Pds5-Scc1 interface leads to loss of sister chromatid cohesion and cell inviability.

Conclusions:

• The Pds5-Scc1 interaction is essential for maintaining sister chromatid cohesion.
• Understanding this interaction provides insights into the regulation of genome stability.