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Publication Abstract from PubMed

The cGMP phosphodiesterase of rod photoreceptor cells, PDE6, is the key effector enzyme in phototransduction. Two large catalytic subunits, PDE6alpha and -beta, each contain one catalytic domain and two non-catalytic GAF domains, whereas two small inhibitory PDE6gamma subunits allow tight regulation by the G protein transducin. The structure of holo-PDE6 in complex with the ROS-1 antibody Fab fragment was determined by cryo-electron microscopy. The approximately 11 A map revealed previously unseen features of PDE6, and each domain was readily fit with high resolution structures. A structure of PDE6 in complex with prenyl-binding protein (PrBP/delta) indicated the location of the PDE6 C-terminal prenylations. Reconstructions of complexes with Fab fragments bound to N or C termini of PDE6gamma revealed that PDE6gamma stretches from the catalytic domain at one end of the holoenzyme to the GAF-A domain at the other. Removal of PDE6gamma caused dramatic structural rearrangements, which were reversed upon its restoration.

Domain Organization and Conformational Plasticity of the G Protein Effector, PDE6.,Zhang Z, He F, Constantine R, Baker ML, Baehr W, Schmid MF, Wensel TG, Agosto MA J Biol Chem. 2015 May 15;290(20):12833-43. doi: 10.1074/jbc.M115.647636. Epub, 2015 Mar 25. PMID:25809480^[1]

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