laboratoire de physique statistique
 
 
laboratoire de physique statistique

Publications

Rechercher
2010 


Jean-François ALLEMAND 


2
P U B L I C A T I O N S

S E L E C T I O N N E R
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2010
MAGNETIC TWEEZERS FOR THE STUDY OF DNA TRACKING MOTORS - Manosas, Maria and Meglio, Adrien and Spiering, Michelle M. and Ding, Fangyuan and Benkovic, Stephen J. and Barre, Francois-Xavier and Saleh, Omar A. and Allemand, Jean Francois and Bensimon, David and Croquette, Vincent
in METHODS IN ENZYMOLOGY, VOL 475: SINGLE MOLECULE TOOLS, PT B: SUPER-RESOLUTION, PARTICLE TRACKING, MULTIPARAMETER, AND FORCE BASED METHODS edited by Walter, NG (2010) 
LPS


Abstract : Single-molecule manipulation methods have opened a new vista on the study of molecular motors. Here we describe the use of magnetic traps for the investigation of the mechanism of DNA based motors, in particular helicases and translocases.
Separating speed and ability to displace roadblocks during DNA translocation by FtsK - Crozat, Estelle and Meglio, Adrien and Allemand, Jean-Francois and Chivers, Claire E. and Howarth, Mark and Venien-Bryan, Catherine and Grainge, Ian and Sherratt, David J.
EMBO JOURNAL 291423-1433 (2010) 
LPS


Abstract : FtsK translocates dsDNA directionally at >5 kb/s, even under strong forces. In vivo, the action of FtsK at the bacterial division septum is required to complete the final stages of chromosome unlinking and segregation. Despite the availability of translocase structures, the mechanism by which ATP hydrolysis is coupled to DNA translocation is not understood. Here, we use covalently linked translocase subunits to gain insight into the DNA translocation mechanism. Covalent trimers of wild-type subunits dimerized efficiently to form hexamers with high translocation activity and an ability to activate XerCD-dif chromosome unlinking. Covalent trimers with a catalytic mutation in the central subunit formed hexamers with two mutated subunits that had robust ATPase activity. They showed wild-type translocation velocity in single-molecule experiments, activated translocation-dependent chromosome unlinking, but had an impaired ability to displace either a triplex oligonucleotide, or streptavidin linked to biotin-DNA, during translocation along DNA. This separation of translocation velocity and ability to displace roadblocks is more consistent with a sequential escort mechanism than stochastic, hand-off, or concerted mechanisms. The EMBO Journal (2010) 29, 1423-1433. doi: 10.1038/emboj.2010.29; Published online 8 April 2010