BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Plasmid addiction and toxin-antitoxin systems : paradigms for the 
 study - Lode Wyns
DTSTART:20080206T103000Z
DTEND:20080206T113000Z
UID:TALK9757@talks.cam.ac.uk
CONTACT:Giorgio Favrin
DESCRIPTION:Plasmid addiction or Toxin-Antitoxin systems (TA systems)are r
 esponsible for post-segregational killing in bacteria when the plasmid har
 boring the system is lost.These systems are widespread and also a multitud
 e of chromosomally located copies have been found.These might function as 
 regulatory switches under stress conditions.\nWe have mainly studied the s
 tructures and biophysics of the CcdA-CcdB (antitoxin /toxin) system.\nHere
  the toxin binds Gyrase and induces it to become a poison.The CcdA antitox
 in inhibits CcdB's action\,it rejuvenates the Gyrase-Ccdb complex and bind
 ing of CcdB turns CcdA into a stronger autoregulatory transcription factor
 .\nThe interactions systematically involve IDP regions that structure upon
  binding.The relevant peptides - corresponding to the intrinsically disord
 ered part of CcdA - show remarkably high affinities\,also rejuvenate the p
 oisoned Gyrase by an allosteric zipper mechanism and this both in vitro an
 d in vivo.\n\n
LOCATION:Unilever Lecture Theatre\, Unilever Centre\, Department of Chemis
 try
END:VEVENT
END:VCALENDAR