Genome organisation

Discovery of a new way protein helps to organise DNA inside our cells.

Researchers have discovered a groundbreaking method in which the ‘structural maintenance of chromosomes’ (SMC) protein helps to organise DNA inside our cells.

Using advanced imaging techniques and computer simulations, the team which includes researchers from the University of Edinburgh, University of Strathclyde and Seoul National University, uncovered that the shape and binding of SMC proteins enable them to control DNA loops efficiently, without making too many mistakes.

The teams found that SMC proteins have a unique geometric shape, which naturally directs them to form DNA loops in a specific direction and orientation. This geometric constraint may be crucial for arranging genetic material but wasn't fully understood before. This study offers insights that could apply to many organisms, enhancing our understanding of genome organisation.

Dr Davide Michieletto, Royal Society Research Fellow commented:

SMC proteins have recently been discovered to perform so-called ‘loop extrusion’ but no one understands how they do it so effectively in the crowded and entangled environment of a cell’s nucleus. In this study we provide experimental and computational evidence that SMC structure itself may guide efficient loop extrusion by imposing a geometric constraint on its angular motion. We argue that anisotropy and broken detailed balance are the necessary ingredients to explain SMC efficient loop extrusion in vitro and in vivo.

The findings are published in the journal Nucleic Acids Research where they are highlighted as a ‘breakthrough paper’ – the top 1% most influential papers in the field. The journal states that such articles appear to solve a long-standing problem in their field or provide exceptional new insight and understanding into an area of research that will clearly motivate and guide new research opportunities and directions.