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.


1jai

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1jai.gif|left|200px]]
+
{{Seed}}
 +
[[Image:1jai.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1jai| PDB=1jai | SCENE= }}
{{STRUCTURE_1jai| PDB=1jai | SCENE= }}
-
'''H-RAS P21 PROTEIN MUTANT G12P, COMPLEXED WITH GUANOSINE-5'-[BETA,GAMMA-METHYLENE] TRIPHOSPHATE AND MANGANESE'''
+
===H-RAS P21 PROTEIN MUTANT G12P, COMPLEXED WITH GUANOSINE-5'-[BETA,GAMMA-METHYLENE] TRIPHOSPHATE AND MANGANESE===
-
==Overview==
+
<!--
-
GTP and ATP hydrolysing proteins have an absolute requirement for a divalent cation, which is usually Mg2+, as a cofactor in the enzymatic reaction. Other phosphoryl transfer enzymes employ more than one divalent ion for the enzymatic reaction. It is shown here for p21ras, a well studied example of GTP hydrolysing proteins, that the GTP-hydrolysis rate is significantly faster if Mg2+ is replaced by Mn2+, both in the presence or absence of its GTPase-activating protein Ras-GAP. This effect is not due to a different stoichiometry of metal ion binding, since one metal ion is sufficient for full enzymatic activity. To determine the role of the metal ion, the crystal structure of p21(G12P). GppCp complexed with Mn2+ was determined and shown to be very similar to the corresponding p21(G12P). GppCp.Mg2+ structure. Especially the coordination sphere around the metal ions is very similar, and no second metal ion binding site could be detected, consistent with the assumption that one metal ion is sufficient for GTP hydrolysis. In order to explain the biochemical differences, we analysed the GTPase reaction mechanism with a linear free energy relationships approach. The result suggests that the reaction mechanism is not changed with Mn2+ but that the transition metal ion Mn2+ shifts the pKa of the gamma-phosphate by almost half a unit and increases the reaction rate due to an increase in the basicity of GTP acting as the general base. This suggests that the intrinsic GTPase reaction could be an attractive target for anti-cancer drug design. By using Rap1A and Ran, we show that the acceleration of the GTPase by Mn2+ appears to be a general phenomenon of GTP-binding proteins.
+
The line below this paragraph, {{ABSTRACT_PUBMED_9102473}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 9102473 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_9102473}}
==About this Structure==
==About this Structure==
Line 31: Line 35:
[[Category: Gtp-binding]]
[[Category: Gtp-binding]]
[[Category: Signal transduction]]
[[Category: Signal transduction]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 20:58:55 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 1 16:34:07 2008''

Revision as of 15:19, 1 July 2008

Image:1jai.png

Template:STRUCTURE 1jai

H-RAS P21 PROTEIN MUTANT G12P, COMPLEXED WITH GUANOSINE-5'-[BETA,GAMMA-METHYLENE] TRIPHOSPHATE AND MANGANESE

Template:ABSTRACT PUBMED 9102473

About this Structure

1JAI is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

Reference

The role of the metal ion in the p21ras catalysed GTP-hydrolysis: Mn2+ versus Mg2+., Schweins T, Scheffzek K, Assheuer R, Wittinghofer A, J Mol Biol. 1997 Mar 7;266(4):847-56. PMID:9102473

Page seeded by OCA on Tue Jul 1 16:34:07 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

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