BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Sophie Jackson (University of Cambridge) DTSTART:20240111T150000Z DTEND:20240111T160000Z DTSTAMP:20260423T022928Z UID:GEOTOP-A/77 DESCRIPTION:Title: The What\, Where\, How and Why of Topological Knots in Proteins\nby Sophie Jackson (University of Cambridge) as part of GEOTOP-A seminar\n\n\n Abstract\nFor decades it was thought that topological knots would never be formed by the polypeptide chain of any protein\, knotting being incompati ble with folding mechanisms. However\, we now know that many proteins fol d and form three-dimensional structures in which the chain crosses itself and threads through loop(s) to form knots. Proteins with very deep knots\, i.e.\, a large part of the chain has passed through a knotting loop to fo rm the knot have been identified\, and four different classes of knots hav e been found embedded in protein strucutres: 3-1\, 4-1\, 5-2\, and 6-1 kn ots. In addition\, recently it has been established that a single polypept ide chain can contain more than one knot - several examples of tandem tref oil knotted proteins have been characterised. With the advent of the mach ine-learning based protein structure algorithm AlphaFold\, several new cla sses of knotted protein have been predicted although their knotted structu res have not yet been verified experimentally. Over twenty years\, numero us experimental and computational studies on knotted proteins have investi gated how such structures might form\, in addition\, to the properties of the knotted structure and whether they differ significantly or not from un knotted proteins. In this talk\, I will review the field and explain 1) w hat knots are found in proteins and where they are within the folded struc tures\, 2) the mechanisms by which knotted may fold\, i.\, how the knots g et there\, and 3) why proteins may have evolved to form knotted structures . The talk will provide background on twenty years of research as well as discussing some state-of-the-art studies on designing proteins with novel knotted folds\, as well as watching knotted proteins unfold and transloca te through narrow pores.\n LOCATION:https://researchseminars.org/talk/GEOTOP-A/77/ END:VEVENT END:VCALENDAR