G protein of G protein coupled receptors are attached to?
Ans. is 'b' i.e.,Carboxyterminal end* G protein coupled receptors are receptors which are coupled to G protein* G proteins are proteins which get activated on binding to GTP* There are two types of G proteins# Small G proteins# Heterotrimeric G proteins* G protein coupled receptors are coupled to heterotrimeric G proteins with a,p,y subunits* The receptors cross the cell membrane 7 times. That makes them look like a snake. Hence they are called as serpentine receptors.* These receptors being proteins, have an aminoterminal end and a carboxy terminal end. Aminoterminal end faces the extracellular side and the carboxy terminal end faces the cytoplasm. To this carboxy terminal end, is attached the G protein, with a, b, g subunits.
Aminoterminal end
Carboxyterminal end
Third transmembrane domain
Seventh transmembrane domain
Membrane Structure & Function