Monomeric G-protein

 

A monomeric G-protein ( also known as small G protein or small GTPases, is the umbrella term for a family of signal transducing proteins. These comprise of: Rab, Arf, Ras, Ran and Rho, which are also vital in the growth of cells, as well as cell transport, motility, cytokinesis and cell differentiation. Monomeric G proteins comprise of two forms, 1.) an 'inactive' form in which the monomeric G-protein is bound to GDP ( guanosine diphosphate), and 2.) the 'active'  form in which the Monomeric G-protein is bound to GTP ( guanosine triphosphate). Notably, Monomeric G-proteins are small,( ranging around 20-25 Kd,) compared with larger types of G protein like Heterotrimeric proteins ( which are typically 30-35 Kd).

References:

Berg et al., (2006) Biochemistry, 6th edition, New York. Page 432