My research interest is Intracellular DNA topology, its regulation and its bilogical implications. I investigate the occurrence of DNA supercoils, knots and catenanes across eukaryotic chromosomes; the molecular mechanisms that generate, stabilize and dissolve them; and their interplay with genome transactions.

The iconic double helical shape of DNA has deep implications in genome biology.

  • As DNA molecules are extremely long, they are condensed into chromatin fibers. However, since DNA needs to unfold and unwind during gene transcription and chromosome replication, DNA molecules undergo severe topological constraints (twisting tension, supercoiling, knotting and catenation).

  • A ubiquitous class of enzymes, termed topoisomerases, resolve DNA topological problems by producing transient DNA breaks and passing DNA strands throughout each other. Numerous antibiotics and anti-cancer drugs kill cells by interfering the activity of topoisomerases.

  • DNA topoisomerases, along with other enzymatic activities that alter chromatin architecture (RNA &DNA polymerases, DNA helicases, nucleosome remodellers, SMCs complexes), determine where DNA twisting and coling is generated or dissipated, and which DNA entanglements must be preserved or eliminated.


Joaquim Roca 
Molecular Biology Institute of Barcelona (IBMB)
Baldiri Reixac 10, 08028 Barcelona, Spain




J Roca  2018