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4c0a

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Revision as of 22:13, 25 December 2014

Arf1(Delta1-17)in complex with BRAG2 Sec7-PH domain

Structural highlights

4c0a is a 8 chain structure with sequence from Bos taurus and Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:
Resources:	FirstGlance, OCA, RCSB, PDBsum

Function

[ARF1_BOVIN] GTP-binding protein that functions as an allosteric activator of the cholera toxin catalytic subunit, an ADP-ribosyltransferase. Involved in protein trafficking among different compartments. Modulates vesicle budding and uncoating within the Golgi complex. Deactivation induces the redistribution of the entire Golgi complex to the endoplasmic reticulum, suggesting a crucial role in protein trafficking. In its GTP-bound form, its triggers the association with coat proteins with the Golgi membrane. The hydrolysis of ARF1-bound GTP, which is mediated by ARFGAPs proteins, is required for dissociation of coat proteins from Golgi membranes and vesicles.

Publication Abstract from PubMed

The mechanisms whereby guanine nucleotide exchange factors (GEFs) coordinate their subcellular targeting to their activation of small GTPases remain poorly understood. Here we analyzed how membranes control the efficiency of human BRAG2, an ArfGEF involved in receptor endocytosis, Wnt signaling, and tumor invasion. The crystal structure of an Arf1-BRAG2 complex that mimics a membrane-bound intermediate revealed an atypical PH domain that is constitutively anchored to the catalytic Sec7 domain and interacts with Arf. Combined with the quantitative analysis of BRAG2 exchange activity reconstituted on membranes, we find that this PH domain potentiates nucleotide exchange by about 2,000-fold by cumulative conformational and membrane-targeting contributions. Furthermore, it restricts BRAG2 activity to negatively charged membranes without phosphoinositide specificity, using a positively charged surface peripheral to but excluding the canonical lipid-binding pocket. This suggests a model of BRAG2 regulation along the early endosomal pathway that expands the repertoire of GEF regulatory mechanisms. Notably, it departs from the auto-inhibitory and feedback loop paradigm emerging from studies of SOS and cytohesins. It also uncovers a novel mechanism of unspecific lipid-sensing by PH domains that may allow sustained binding to maturating membranes.

Integrated Conformational and Lipid-Sensing Regulation of Endosomal ArfGEF BRAG2.,Aizel K, Biou V, Navaza J, Duarte LV, Campanacci V, Cherfils J, Zeghouf M PLoS Biol. 2013 Sep;11(9):e1001652. doi: 10.1371/journal.pbio.1001652. Epub 2013 , Sep 10. PMID:24058294^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Aizel K, Biou V, Navaza J, Duarte LV, Campanacci V, Cherfils J, Zeghouf M. Integrated Conformational and Lipid-Sensing Regulation of Endosomal ArfGEF BRAG2. PLoS Biol. 2013 Sep;11(9):e1001652. doi: 10.1371/journal.pbio.1001652. Epub 2013 , Sep 10. PMID:24058294 doi:10.1371/journal.pbio.1001652

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/4c0a"

@@ Line 6: / Line 6: @@
 <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4c0a FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4c0a OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4c0a RCSB], [http://www.ebi.ac.uk/pdbsum/4c0a PDBsum]</span></td></tr>
 </table>
+== Function ==
+[[http://www.uniprot.org/uniprot/ARF1_BOVIN ARF1_BOVIN]] GTP-binding protein that functions as an allosteric activator of the cholera toxin catalytic subunit, an ADP-ribosyltransferase. Involved in protein trafficking among different compartments. Modulates vesicle budding and uncoating within the Golgi complex. Deactivation induces the redistribution of the entire Golgi complex to the endoplasmic reticulum, suggesting a crucial role in protein trafficking. In its GTP-bound form, its triggers the association with coat proteins with the Golgi membrane. The hydrolysis of ARF1-bound GTP, which is mediated by ARFGAPs proteins, is required for dissociation of coat proteins from Golgi membranes and vesicles.
 <div style="background-color:#fffaf0;">
 == Publication Abstract from PubMed ==

4c0a

From Proteopedia

Revision as of 22:13, 25 December 2014

Arf1(Delta1-17)in complex with BRAG2 Sec7-PH domain

Structural highlights

Function

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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