************第３４回尾張コンプレックスセミナー*************
　　　　
Title   ：  Conformational changes and fluctuations of molecular switch　
             
Speaker ：　 Chigusa Kobayashi

Affiliation：Saito Lab., Institute for Molecular Science

Date    ：　Th. Nov. 19th, 1:30pm (Almost one hour)

Place   :   Room 616, Graduate School of Information Science

Abstract：
Ras superfamily is known well as signal transduction protein.  Ras is
activated by binding of GTP and binds to effectors for the signal
trunsduction related to the regulation of cell proliferation.  It is
inactivated by the hydrolysis of GTP.  The GTPase activity is enhanced by
the binding of GTPase activating protein,GAP.  X-ray crystallography has
revealed conformational changes in two regions, called switch regions,
around a nucleotide binding site along the reaction.  It is also
experimentally known that there are two distinct states in the GTP-bound
Ras, state 1 and state 2.  State 2 is an active state for the cell growth,
while state 1 has a low affinity to the effectors for the cell growth.  In
this study, we investigate the conformational changes and fluctuations of
the switch regions in GTP-, i.e. states 1 and 2, and GDP-bound states by
using MD simulation.  We also investigate the structure and fluctuation
in the GAP-GTP-bound state and the role of the binding of GAP.

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