3OHM: Crystal Structure Of Activated G Alpha Q Bound To Its Effector Phospholipase C Beta 3

Citation:
Abstract
Transmembrane signals initiated by a broad range of extracellular stimuli converge on nodes that regulate phospholipase C (PLC)-dependent inositol lipid hydrolysis for signal propagation. We describe how heterotrimeric guanine nucleotide-binding proteins (G proteins) activate PLC-betas and in turn are deactivated by these downstream effectors. The 2.7-angstrom structure of PLC-beta3 bound to activated Galpha(q) reveals a conserved module found within PLC-betas and other effectors optimized for rapid engagement of activated G proteins. The active site of PLC-beta3 in the complex is occluded by an intramolecular plug that is likely removed upon G protein-dependent anchoring and orientation of the lipase at membrane surfaces. A second domain of PLC-beta3 subsequently accelerates guanosine triphosphate hydrolysis by Galpha(q), causing the complex to dissociate and terminate signal propagation. Mutations within this domain dramatically delay signal termination in vitro and in vivo. Consequently, this work suggests a dynamic catch-and-release mechanism used to sharpen spatiotemporal signals mediated by diverse sensory inputs.
PDB ID: 3OHMDownload
MMDB ID: 85808
PDB Deposition Date: 2010/8/17
Updated in MMDB: 2010/11
Experimental Method:
x-ray diffraction
Resolution: 2.7  Å
Source Organism:
Mus musculus
Similar Structures:
Biological Unit for 3OHM: dimeric; determined by author and by software (PISA)
Molecular Components in 3OHM
Label Count Molecule
Proteins (2 molecules)
1
Guanine Nucleotide-binding Protein G(q) Subunit Alpha(Gene symbol: Gnaq)
Molecule annotation
1
1-phosphatidylinositol-4,5-bisphosphate Phosphodiesterase Beta-3(Gene symbol: PLCB3)
Molecule annotation
Chemicals (7 molecules)
1
1
2
1
3
1
4
1
5
3
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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