This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.


1svk

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1svk.gif|left|200px]]
+
{{Seed}}
 +
[[Image:1svk.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1svk| PDB=1svk | SCENE= }}
{{STRUCTURE_1svk| PDB=1svk | SCENE= }}
-
'''Structure of the K180P mutant of Gi alpha subunit bound to AlF4 and GDP'''
+
===Structure of the K180P mutant of Gi alpha subunit bound to AlF4 and GDP===
-
==Overview==
+
<!--
-
Heterotrimeric G protein alpha (G alpha) subunits possess intrinsic GTPase activity that leads to functional deactivation with a rate constant of approximately 2 min(-1) at 30 degrees C. GTP hydrolysis causes conformational changes in three regions of G alpha, including Switch I and Switch II. Mutation of G202--&gt;A in Switch II of G alpha(i1) accelerates the rates of both GTP hydrolysis and conformational change, which is measured by the loss of fluorescence from Trp-211 in Switch II. Mutation of K180--&gt;P in Switch I increases the rate of conformational change but decreases the GTPase rate, which causes transient but substantial accumulation of a low-fluorescence G alpha(i1).GTP species. Isothermal titration calorimetric analysis of the binding of (G202A)G alpha(i1) and (K180P)G alpha(i1) to the GTPase-activating protein RGS4 indicates that the G202A mutation stabilizes the pretransition state-like conformation of G alpha(i1) that is mimicked by the complex of G alpha(i1) with GDP and magnesium fluoroaluminate, whereas the K180P mutation destabilizes this state. The crystal structures of (K180P)G alpha(i1) bound to a slowly hydrolyzable GTP analog, and the GDP.magnesium fluoroaluminate complex provide evidence that the Mg(2+) binding site is destabilized and that Switch I is torsionally restrained by the K180P mutation. The data are consistent with a catalytic mechanism for G alpha in which major conformational transitions in Switch I and Switch II are obligate events that precede the bond-breaking step in GTP hydrolysis. In (K180P)G alpha(i1), the two events are decoupled kinetically, whereas in the native protein they are concerted.
+
The line below this paragraph, {{ABSTRACT_PUBMED_15128951}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 15128951 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_15128951}}
==About this Structure==
==About this Structure==
Line 32: Line 36:
[[Category: Gi alpha subunit]]
[[Category: Gi alpha subunit]]
[[Category: K180p mutation]]
[[Category: K180p mutation]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 09:11:16 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 06:47:42 2008''

Revision as of 03:47, 28 July 2008

Image:1svk.png

Template:STRUCTURE 1svk

Structure of the K180P mutant of Gi alpha subunit bound to AlF4 and GDP

Template:ABSTRACT PUBMED 15128951

About this Structure

1SVK is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.

Reference

Uncoupling conformational change from GTP hydrolysis in a heterotrimeric G protein alpha-subunit., Thomas CJ, Du X, Li P, Wang Y, Ross EM, Sprang SR, Proc Natl Acad Sci U S A. 2004 May 18;101(20):7560-5. Epub 2004 May 5. PMID:15128951

Page seeded by OCA on Mon Jul 28 06:47:42 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1svk"
Personal tools