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PHYSICS
AND ASTRONOMY
Science
at the Edge
Friday,
May 21, 2010
11:30a
1400
Biomedical & Physical Sciences Bldg
Refreshments
at 11:15a in 1400 BPS Bldg
Jose
Onuchic
University
of California at San Diego
“sharing
the energy landscape for folding and function: from small proteins to molecular
motors”
Globally
the energy landscape of a folding protein resembles a partially rough funnel
with reduced energetic frustration. A consequence of minimizing energetic
frustration is that the topology of the native fold also plays a major role in
the folding mechanism. Some folding motifs are easier to design than
other suggesting the possibility that evolution not only selected sequences
with sufficiently small energetic frustration but also selected more easily
designable native structures. The overall structure of the on-route and
off-route (traps) intermediates for the folding of more complex proteins is
also strongly influenced by topology.
Many
cellular functions rely on interactions among proteins and between proteins and
nucleic acids. The limited success of binding predictions may suggest
that the physical and chemical principles of protein binding have to be
revisited to correctly capture the essence of protein recognition. Going
beyond folding, the power of reduced models to study the physics of protein
assembly will be discussed. Since energetic frustration is sufficiently
small, native topology-based models, which correspond to perfectly unfrustrated
energy landscapes, have shown that binding mechanisms are robust and governed
primarily by the protein’s native topology. These models
impressively captured many of the binding characteristics found in experiments
and highlighted the fundamental role of flexibility in binding. Deciphering
and quantifying the key ingredients for biological self-assembly is invaluable
to reading out genomic sequences and understanding cellular interaction
networks. Going even beyond binding and recognition, we will be
discussing the energy landscape for the molecular motor kinesin.
***To
make an appointment to meet with the speaker, contact Prof. Lisa Lapidus ([log in to unmask])***
Kim Crosslan
Undergraduate
Secretary, Dept. Physics & Astronomy
Michigan State
University
1312 Biomedical
& Physical Sciences
East
Lansing, MI 48824
517-884-5531