Globular actin is a monomer that is composed of a larger cleft (active site) and a smaller cleft (allosteric site). Ser14, Ser33, His73, Glu72, Tyr69 are hydrophilic residues of active site. The tertiary structure consists of four major subdomains. Subdomain 1 and 3 form the smaller cleft and subdomain 2 and 4 form the larger cleft. It is filamentous when polymerized (F-actin).
Function
G-actin can be polymerized to form filamentous F-actin. It is involved in cell motility in prokaryotic and eukaryotic cells. It builds a ladder on which the myosin filament climbs, which in turn causes muscle contractions and other cell movements. It also maintains structure and makes up some of the cytoskeleton of the cell. It orients cellular processes based on space and time.
Disease
Relevance
Structural highlights
