I am a postdoctoral Fellow in Madhu Srinivasan’s laboratory at the Department of Biochemistry, University of Oxford and a Fellow of Trinity College, Oxford and of the Royal Society. I am a member of the Austrian Academy of Sciences and a foreign honorary member of the American Academy of Arts and Sciences.
While a senior scientist at the Research Institute of Molecular Pathology in Vienna, my group identified the cohesin complex that regulates the topology of eukaryotic chromosomes during interphase and holds sister chromatids together following their genesis during S phase. We also elucidated the mechanism by which cohesion is destroyed at the metaphase to anaphase transition, namely cleavage of cohesin’s kleisin subunit by separase. Separase is a thiol protease activated through ubiquitinylation of its inhibitory chaperone securin, by the anaphase-promoting complex or cyclosome. A collaboration between my group and Jan Löwe’s in analysing cohesin’s structure led to the notion that it holds sister DNAs together by entrapping them inside a tripartite ring formed by pairwise interactions between its Smc1, Smc3 and kleisin subunits. My current work concerns the mechanism by which sister DNAs are entrapped by cohesin rings during DNA replication.