In neither case does the inhibitor compete with the substrate for the same binding site, so the inhibition cannot be overcome by increasing the substrate concentration.

TLS Online TPP Program

#Id: 9040

#XL - T Zoology

GPCR function as GEFs for heterotrimeric G protein.

TLS Online TPP Program

#Id: 9041

#XL - T Zoology

TLS Online TPP Program

#Id: 9042

#XL - T Zoology

Heterotrimeric G proteins directly bind to and are activated by G protein coupled receptors.

TLS Online TPP Program

#Id: 9043

#XL - T Zoology

Switching mechanism of monomeric G proteins 

“On” state, switch I and switch II, are bound to the terminal γ phosphate of GTP with the backbone amide groups of conserved T & G.

TLS Online TPP Program

#Id: 9044

#XL - T Zoology

TLS Online TPP Program

#Id: 9045

#XL - T Zoology

Switching mechanism of monomeric G proteins 

“Off” state, Removal of the γ phosphate by GTPase-catalyzed hydrolysis causes switch I and switch II to relax into a different conformation