1a0r

From Proteopedia

(Difference between revisions)

Revision as of 20:58, 25 December 2014

HETEROTRIMERIC COMPLEX OF PHOSDUCIN/TRANSDUCIN BETA-GAMMA

Structural highlights

1a0r is a 3 chain structure with sequence from Bos taurus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:
NonStd Res:
Resources:	FirstGlance, OCA, RCSB, PDBsum

Function

[GBB1_HUMAN] Guanine nucleotide-binding proteins (G proteins) are involved as a modulator or transducer in various transmembrane signaling systems. The beta and gamma chains are required for the GTPase activity, for replacement of GDP by GTP, and for G protein-effector interaction.^[1] [PHOS_BOVIN] Inhibits the transcriptional activation activity of the cone-rod homeobox CRX (By similarity). May participate in the regulation of visual phototransduction or in the integration of photoreceptor metabolism. [GBG1_BOVIN] Guanine nucleotide-binding proteins (G proteins) are involved as a modulator or transducer in various transmembrane signaling systems. The beta and gamma chains are required for the GTPase activity, for replacement of GDP by GTP, and for G protein-effector interaction.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

BACKGROUND: Phosducin binds tightly to the beta gamma subunits (Gt beta gamma) of the heterotrimeric G protein transducin, preventing Gt beta gamma reassociation with Gt alpha-GDP and thereby inhibiting the G-protein cycle. Phosducin-like proteins appear to be widely distributed and may play important roles in regulating many heterotrimeric G-protein signaling pathways. RESULTS: The 2.8 A crystal structure of a complex of bovine retinal phosducin with Gt beta gamma shows how the two domains of phosducin cover one side and the top of the seven-bladed beta propeller of Gt beta gamma. The binding of phosducin induces a distinct structural change in the beta propeller of Gt beta gamma, such that a small cavity opens up between blades 6 and 7. Electron density in this cavity has been assigned to the farnesyl moiety of the gamma subunit. CONCLUSIONS: beta gamma subunits of heterotrimeric G proteins can exist in two distinct conformations. In the R (relaxed) state, corresponding to the structure of the free beta gamma or the structure of beta gamma in the alpha beta gamma heterotrimer, the hydrophobic farnesyl moiety of the gamma subunit is exposed, thereby mediating membrane association. In the T (tense) state, as observed in the phosducin-Gt beta gamma structure, the farnesyl moiety of the gamma subunit is effectively buried in the cavity formed between blades 6 and 7 of the beta subunit. Binding of phosducin to Gt beta gamma induces the formation of this cavity, resulting in a switch from the R to the T conformation. This sequesters beta gamma from the membrane to the cytosol and turns off the signal-transduction cascade. Regulation of this membrane association/dissociation switch of Gt beta gamma by phosducin may be a general mechanism for attenuation of G protein coupled signal transduction cascades.

Phosducin induces a structural change in transducin beta gamma.,Loew A, Ho YK, Blundell T, Bax B Structure. 1998 Aug 15;6(8):1007-19. PMID:9739091^[2]

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

References

↑ Johnston CA, Kimple AJ, Giguere PM, Siderovski DP. Structure of the parathyroid hormone receptor C terminus bound to the G-protein dimer Gbeta1gamma2. Structure. 2008 Jul;16(7):1086-94. PMID:18611381 doi:http://dx.doi.org/10.1016/j.str.2008.04.010
↑ Loew A, Ho YK, Blundell T, Bax B. Phosducin induces a structural change in transducin beta gamma. Structure. 1998 Aug 15;6(8):1007-19. PMID:9739091

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 See Also
6 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://proteopedia.org/wiki/index.php/1a0r"

@@ Line 7: / Line 7: @@
 <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=1a0r FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1a0r OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1a0r RCSB], [http://www.ebi.ac.uk/pdbsum/1a0r PDBsum]</span></td></tr>
 </table>
+== Function ==
+[[http://www.uniprot.org/uniprot/GBB1_HUMAN GBB1_HUMAN]] Guanine nucleotide-binding proteins (G proteins) are involved as a modulator or transducer in various transmembrane signaling systems. The beta and gamma chains are required for the GTPase activity, for replacement of GDP by GTP, and for G protein-effector interaction.<ref>PMID:18611381</ref>  [[http://www.uniprot.org/uniprot/PHOS_BOVIN PHOS_BOVIN]] Inhibits the transcriptional activation activity of the cone-rod homeobox CRX (By similarity). May participate in the regulation of visual phototransduction or in the integration of photoreceptor metabolism. [[http://www.uniprot.org/uniprot/GBG1_BOVIN GBG1_BOVIN]] Guanine nucleotide-binding proteins (G proteins) are involved as a modulator or transducer in various transmembrane signaling systems. The beta and gamma chains are required for the GTPase activity, for replacement of GDP by GTP, and for G protein-effector interaction.
 == Evolutionary Conservation ==
 [[Image:Consurf_key_small.gif|200px|right]]

1a0r

From Proteopedia

Revision as of 20:58, 25 December 2014

HETEROTRIMERIC COMPLEX OF PHOSDUCIN/TRANSDUCIN BETA-GAMMA

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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