Physics (Internal)

Stochastic pause-and-translocation of molecular motors: distributions of dwell-times of kinesin and ribosome

This event is part of the Biophysics/Condensed Matter Seminar Series.

Abstract: Living matter is governed by the same laws of physics and
chemistry which describe the structure and dynamics of non-living system.
However, several special “processes”, which take place in living matter,
never occur in non-living systems. Many of these processes are driven by
molecular motors. These devices are either proteins or macromolecular
complexes which move along filamentous tracks utilizing some form of input
energy. In contrast to their macroscopic counterparts, these nano-machines
are (i) made of soft matter, (ii) driven by isothermal engines, (iii) far
from thermodynamic equilibrium, and (iv) their dynamics is dominated by
viscous forces and thermal noise. One characteristic feature of their
"directed", albeit noisy, movements is an alternating sequence of pause
and translocation. In this talk I'll discuss how important "hidden"
informations on the kinetics of such motors can be extracted from the
statistics of the durations of pause+translocation. I'll present our
recent results on dwell-time distributions of two motors, namely,
a member of the kinesin superfamily and the ribosome. I'll also discuss the
theory of collective spatio-temporal organization of the motors on a
track.