World Journal of
Pharmaceutical and Life Sciences

HOW DO SMALL GTPase REGULATE MICROFILAMENT ASSEMBLY

*Miti Bhardwaj

ABSTRACT

Small GTPase is a kind of GTP-binding protein commonly found in eukaryotic cells. It plays an important role in cytoskeletal reorganisation, cell polarity, cell cycle progression, gene expression and many other significant events in cells, such as the interaction with foreign particles. The most prominent member of the small GTPase family is the Ras GTPase, thus the family is also called the Ras superfamily. The analysis of the small GTPase protein crystal structure indicates that the GTP binding domain of this type of protein can be subdivided into five relatively conserved motifs G1–G5. G1 motif (I) is a purine nucleotide binding signal; G2 motif (E) is in one of two segments that redirects with GDP or GTP binding function and provides major component of the effector binding surface; G3 motif (II) is related to the binding of nucleotide-related Mg2+; G4 motif (III) brings the hydrogen bond in contact with the guanine ring; G5 motif (?) makes indirect associations with the guanine nucleotide. Taken together, these elements constitute the conserved ∼20 kDa domain and shared by all Ras superfamily proteins.

[Full Text Article]   [Download Certificate]