# Entanglement in biology; how nature controls the topology of proteins and DNA

The Banff International Research Station will host the " Entanglement in biology; how nature controls the topology of proteins and DNA" workshop from November 17th to November 22nd, 2013.

The last decade has shown that there are an increasing number of known proteins that contain linear open knots or slipknots in their native folded structure. In general, knots in proteins are orders of magnitude less frequent than would be expected for random polymers with similar length, compactness, and flexibility. Explaining why they are so rare is an intriguing question. In principle, the polypeptide chains that fold into knotted native protein structures encounter more thermodynamic problems than unknotted proteins. Therefore, it is believed that knotted protein structures were, in part, eliminated during evolution since proteins that fold slowly and/or non-reproducibly should be evolutionarily disadvantageous for the hosting organisms. Nevertheless, researchers have found several families of proteins that reproducibly form simple knots, complex knots, and slipknots. The discovery of these knotted proteins has challenged our preconceptions about the complexity of biological objects, and has inspired significant research to discover how the tangling properties affect the function of the protein. Curiously, substantial mathematical challenges have arisen. How do we define the terms knot'' and slipknot'' in open chains? How does one rigorously study the entanglement structure found in proteins? With progress, we expect that many challenging theoretical problems will arise. Additionally, over the last decade, while tremendous advances have been made in understanding the tangling of DNA, many mysteries remain. This workshop is conceived in response to recent pioneering experimental discoveries and developments that have taken place in biology, biophysics, and mathematics. To fully understand how nature controls the topology of proteins and DNA, much theoretical, numerical, and experimental progress will be required. This progress requires the effort of top researchers working at the interface of mathematics, biology, chemistry, and physics. This workshop will bridge these fields, inspiring cutting-edge interdisciplinary collaborations, and defining the key problems for the next decade.

The Banff International Research Station for Mathematical Innovation and Discovery (BIRS) is a collaborative Canada-US-Mexico venture that provides an environment for creative interaction as well as the exchange of ideas, knowledge, and methods within the Mathematical Sciences, with related disciplines and with industry. The research station is located at The Banff Centre in Alberta and is supported by Canada's Natural Science and Engineering Research Council (NSERC), the U.S. National Science Foundation (NSF), Alberta's Advanced Education and Technology, and Mexico's Consejo Nacional de Ciencia y Tecnología (CONACYT).

BIRS Scientific Director, Nassif Ghoussoub
E-mail: birs-director[@]birs.ca
http://www.birs.ca/~nassif