Titre du document / Document title

Coupled protein domain motion in Taq polymerase revealed by neutron spin-echo spectroscopy

Auteur(s) / Author(s)

ZIMEI BU ; BIEHL Ralf ; MONKENBUSCH Michael ; RICHTER Dieter ; CALLAWAY David J. E. ;

Résumé / Abstract

Long-range conformational changes in proteins are ubiquitous in biology for the transmission and amplification of signals; such conformational changes can be triggered by small-amplitude, nanosecond protein domain motion.Understanding how conformational changes are initiated requires the characterization of protein domain motion on these timescales and on length scales comparable to protein dimensions. Using neutron spin-echo spectroscopy (NSE), normal mode analysis, and a statistical-mechanical framework, we reveal overdamped, coupled domain motion within DNA polymerase I from Thermus aquaticus (Taq polymerase). This protein utilizes correlated domain dynamics over 70 Å to coordinate nucleotide synthesis and cleavage during DNA synthesis and repair. We show that NSE spectroscopy can determine the domain mobility tensor, which determines the degree of dynamical coupling between domains. The mobility tensor defines the domain velocity response to a force applied to it or to another domain, just as the sails of a sailboat determine its velocity given the applied wind force. The NSE results provide insights into the nature of protein domain motion that are not appreciated by conventional biophysical techniques.

Revue / Journal Title

Proceedings of the National Academy of Sciences of the United States of America   ISSN 0027-8424   CODEN PNASA6 

Source / Source

2005, vol. 102, n^o49, pp. 17646-17651 [6 page(s) (article)]

Langue / Language

Anglais

Editeur / Publisher

National Academy of Sciences of the United States of America, Washington, DC, ETATS-UNIS  (1915) (Revue)

Localisation / Location

INIST-CNRS, Cote INIST : 574, 35400013459897.0210