In: Biology
Actin filaments are the smallest cytoskekton filament with a diameter of 7 nm they are thin ,relatively flexible thread that can be crosslinked together in different sturctures .Actin monomers are called globular actin or G actin .
In addition to monomer binding proteins ,capping proteins have often been implicated in industry polymerization .capping proteins bind to the barbed end of an actin filament and prevent elongation at that end but nucleate elongation from the pointed ,or slow growing end.
The eukaryotic cytoskekton of organism among all taxonomic groups have similar components of actin and tublin for example the protein that is coded by the the ACTG2 gene in humans is completely equivalnet to the homologous present in rats and mice ,even though at a nucliotide level the similarty decreases to 92percent however there are major differneces with the equivalent in prokaryotes where the similarty between nucleotide sequence is between 40-50 percent among different bacteria and archea species .ansestral protein that give rise to the model eukaryotic actin resembles the protein present in modern bacterial cytoskelton.