2fmx

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
(New page: 200px<br /><applet load="2fmx" size="450" color="white" frame="true" align="right" spinBox="true" caption="2fmx, resolution 1.82&Aring;" /> '''An open conformation...)
Line 1: Line 1:
-
[[Image:2fmx.jpg|left|200px]]<br /><applet load="2fmx" size="450" color="white" frame="true" align="right" spinBox="true"
+
[[Image:2fmx.jpg|left|200px]]<br /><applet load="2fmx" size="350" color="white" frame="true" align="right" spinBox="true"
caption="2fmx, resolution 1.82&Aring;" />
caption="2fmx, resolution 1.82&Aring;" />
'''An open conformation of switch I revealed by Sar1-GDP crystal structure at low Mg(2+)'''<br />
'''An open conformation of switch I revealed by Sar1-GDP crystal structure at low Mg(2+)'''<br />
==Overview==
==Overview==
-
Mg2+ is essential for guanosine triphosphatase activity and plays key, roles in guanine nucleotide binding and preserving the structural, integrity of GTP-binding proteins. To understand the structural basis for, Mg2+ function during the GDP/GTP exchange process, we determined the, crystal structure of Delta9-Sar1-GDP at low Mg2+ concentration at 1.8A., Two Sar1-GDP molecules in the crystal form a dimer with Mg2+ presenting, only in molecule B but not in molecule A. The absence of Mg2+ induces, significant conformational changes in the switch I region in molecule A, that shows similarities with those of Ha-Ras bound to Sos. The current, structure reveals an important regulatory role for Mg2+. We suggest that, guanine nucleotide exchange factor may utilize this feature to generate an, open conformation for GDP/GTP exchange. Furthermore, we propose a, mechanism for COPII assembly and disassembly in which dimerization of Sar1, plays an important role.
+
Mg2+ is essential for guanosine triphosphatase activity and plays key roles in guanine nucleotide binding and preserving the structural integrity of GTP-binding proteins. To understand the structural basis for Mg2+ function during the GDP/GTP exchange process, we determined the crystal structure of Delta9-Sar1-GDP at low Mg2+ concentration at 1.8A. Two Sar1-GDP molecules in the crystal form a dimer with Mg2+ presenting only in molecule B but not in molecule A. The absence of Mg2+ induces significant conformational changes in the switch I region in molecule A that shows similarities with those of Ha-Ras bound to Sos. The current structure reveals an important regulatory role for Mg2+. We suggest that guanine nucleotide exchange factor may utilize this feature to generate an open conformation for GDP/GTP exchange. Furthermore, we propose a mechanism for COPII assembly and disassembly in which dimerization of Sar1 plays an important role.
==About this Structure==
==About this Structure==
-
2FMX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Cricetulus_griseus Cricetulus griseus] with SO4, MG and GDP as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2FMX OCA].
+
2FMX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Cricetulus_griseus Cricetulus griseus] with <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=GDP:'>GDP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2FMX OCA].
==Reference==
==Reference==
Line 26: Line 26:
[[Category: sar1]]
[[Category: sar1]]
-
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 10:38:21 2007''
+
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:23:03 2008''

Revision as of 15:23, 21 February 2008

Image:2fmx.jpg

2fmx, resolution 1.82Å

Drag the structure with the mouse to rotate

An open conformation of switch I revealed by Sar1-GDP crystal structure at low Mg(2+)

Overview

Mg2+ is essential for guanosine triphosphatase activity and plays key roles in guanine nucleotide binding and preserving the structural integrity of GTP-binding proteins. To understand the structural basis for Mg2+ function during the GDP/GTP exchange process, we determined the crystal structure of Delta9-Sar1-GDP at low Mg2+ concentration at 1.8A. Two Sar1-GDP molecules in the crystal form a dimer with Mg2+ presenting only in molecule B but not in molecule A. The absence of Mg2+ induces significant conformational changes in the switch I region in molecule A that shows similarities with those of Ha-Ras bound to Sos. The current structure reveals an important regulatory role for Mg2+. We suggest that guanine nucleotide exchange factor may utilize this feature to generate an open conformation for GDP/GTP exchange. Furthermore, we propose a mechanism for COPII assembly and disassembly in which dimerization of Sar1 plays an important role.

About this Structure

2FMX is a Single protein structure of sequence from Cricetulus griseus with , and as ligands. Full crystallographic information is available from OCA.

Reference

An open conformation of switch I revealed by Sar1-GDP crystal structure at low Mg2+., Rao Y, Bian C, Yuan C, Li Y, Chen L, Ye X, Huang Z, Huang M, Biochem Biophys Res Commun. 2006 Sep 29;348(3):908-15. Epub 2006 Aug 1. PMID:16899220

Page seeded by OCA on Thu Feb 21 17:23:03 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/2fmx"
Personal tools