Structural basis for Scc3-dependent cohesin recruitment to chromatin

Area of Science:

• Molecular Biology
• Cell Biology
• Structural Biology

Background:

• The cohesin ring complex is vital for chromosomal processes like sister chromatid cohesion, DNA repair, and gene regulation.
• The mechanism by which cohesin interacts with its chromatin substrate remains largely unknown.

Purpose of the Study:

• To elucidate the structural basis of cohesin's interaction with DNA.
• To identify the specific components and mechanisms involved in cohesin-chromatin engagement.

Main Methods:

• Determined the crystal structure of the budding yeast cohesin subunits Scc3 and Scc1 bound to DNA.
• Performed in vitro DNA binding assays.
• Assessed the functional significance of the identified DNA-binding interface for cohesin enrichment and cell viability.

Main Results:

• Scc3 and Scc1 form a composite DNA interaction module.
• This module binds double-stranded DNA via a conserved, positively charged surface.
• This conserved domain is essential for in vitro DNA binding, chromosomal enrichment, and cell viability.

Conclusions:

• The Scc3-Scc1 DNA-binding interface is critical for recruiting cohesin to chromosomes.
• This interaction is fundamental for cohesin's accurate execution of functions during cell division.