PLC beta 3 Gq: Difference between revisions
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PLC- β3 engages Gαq throughout three regions. First, an extended loop between the third and fourth EF hands of PLC- β3 directly supports switch residues critical for GTP hydrolysis by Gαq. Second, the region of PLC- β3 that connects the catalytic TIM barrel and the C2 domain interacts with both switches 1 and 2 of Gαq. Third, a segment composed of a helix-turn-helix at the C terminus of the C2 domain mostly located within a shallow declivity on the surface of Gαq formed by switch 2 and α3. | PLC- β3 engages Gαq throughout three regions. First, an extended loop between the third and fourth EF hands of PLC- β3 directly supports switch residues critical for GTP hydrolysis by Gαq. Second, the region of PLC- β3 that connects the catalytic TIM barrel and the C2 domain interacts with both switches 1 and 2 of Gαq. Third, a segment composed of a helix-turn-helix at the C terminus of the C2 domain mostly located within a shallow declivity on the surface of Gαq formed by switch 2 and α3. | ||
PLC-β3 interacts with a surface on Gαq that <scene name='70/701452/Fig5/ | PLC-β3 interacts with a surface on Gαq that <scene name='70/701452/Fig5/2'>overlaps almost completely</scene> with portions of Gα subunits needed for engagement of RGS proteins and the effector-binding region. Other effectors are known to engage the <scene name='70/701452/Fig3/2'>effector-binding site</scene> within Gα subunits. There are a large family of regulator of G protein signaling (RGS) proteins that independently accelerates the GTP hydrolysis in the <scene name='70/701452/Fig4/2'>GTPase domain</scene>. | ||
The canonical Gα effector-binding region of Gαq, located between α3 and switch 2, is occupied by a helix-turn-helix (Hα1/Hα2) that immediately follows the C2 domain of PLC- β3. <scene name='70/701452/Pro862/2'>Pro862</scene> of PLC- β3 lies within the turn between Hα1 and Hα2, makes extensive contacts with multiple residues of Gαq, and forms the center of a Gαq-binding interface. | The canonical Gα effector-binding region of Gαq, located between α3 and switch 2, is occupied by a helix-turn-helix (Hα1/Hα2) that immediately follows the C2 domain of PLC- β3. <scene name='70/701452/Pro862/2'>Pro862</scene> of PLC- β3 lies within the turn between Hα1 and Hα2, makes extensive contacts with multiple residues of Gαq, and forms the center of a Gαq-binding interface. | ||