Sandbox 154: Difference between revisions

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<applet load='2zwh' size='275' color='black' frame='true' align='right' caption='Filamentous Actin (F-actin)' scene='Sandbox_154/2zwh_black_domains/1'/>
<applet load='2zwh' size='275' color='black' frame='true' align='right' caption='Filamentous Actin (F-actin)' scene='Sandbox_154/2zwh_black_domains/1'/>
The structure of a single unit of F-actin arises from one polypeptide chain with two domains. The nucleotide binding cleft, site of ATP hydrolysis, can be observed between the two domains. Movement of the domains allows for the open and closed F-actin conformations.  
The structure of a single unit of F-actin arises from one polypeptide chain with two domains. The nucleotide binding cleft, site of ATP hydrolysis, can be observed between the two domains. Movement of the domains allows for the open and closed F-actin conformations.  
Domain movement is made possible by rotation about the <scene name='Sandbox_154/2zwh_helix_domains_2/1'> peptide bonds of residues 141-142 and 335-336</scene>, shown in purple. According to Oda et al., during the transition from G- to F- actin, Domain 2 is believed to tilt 20&deg; and fit itself with Domain 1, thus giving a flatter conformation than the free G-actin. It is not certain whether this flattening occurs before or after ATP hydrolysis<ref name="oda" />. Holmes<ref name="holmes2">PMID:19158779</ref> provides a simplified image of this domain movement and flattening[http://www.nature.com/nature/journal/v457/n7228/fig_tab/457389a_F2.html].
Domain movement is made possible by rotation about the <scene name='Sandbox_154/2zwh_helix_domains_2/1'> peptide bonds of residues 141-142 and 335-336</scene>, shown in purple. According to Oda et al., during the transition from G- to F- actin, Domain 2 is believed to tilt 20&deg; and fit itself with Domain 1, thus giving a flatter conformation than the free G-actin. It is not certain whether this flattening occurs before or after ATP hydrolysis<ref name="oda" />. Holmes<ref name="holmes2"/> provides a simplified image of this domain movement and flattening[http://www.nature.com/nature/journal/v457/n7228/fig_tab/457389a_F2.html].


==== Stability ====
==== Stability ====