Coupling chromosome organization to genome segregation in Archaea

Area of Science:

• Microbiology and Molecular Biology
• Genetics and Genomics
• Cell Biology

Background:

• Chromosome segregation is vital for cell division across all life.
• Mechanisms of chromosome segregation in archaea are not well understood.
• SegA and SegB proteins were previously identified as a minimal partition machine in Sulfolobales.

Purpose of the Study:

• To elucidate the patterns and mechanisms by which SegAB proteins link chromosome organization to genome segregation in archaea.
• To investigate the in vivo function of SegAB proteins in archaeal chromosome partitioning.

Main Methods:

• Chromatin immunoprecipitation sequencing (ChIP-seq) to identify SegB binding sites.
• Gene deletion studies to assess the impact on growth and chromosome segregation.
• Atomic force microscopy (AFM) to analyze DNA compaction and looping by SegB.

Main Results:

• SegB binds to multiple chromosomal sites, primarily intragenic and enriched in specific chromosome compartments.
• SegB forms foci within the nucleoid, localizing towards the cell periphery, suggesting membrane interactions.
• SegB mediates DNA compaction and looping, essential for chromosome condensation and segregation.

Conclusions:

• SegAB proteins play a critical role in bridging chromosome organization with genome segregation in archaea.
• SegAB functions as a key component of the archaeal chromosome partition machinery, influencing DNA structure and localization.