Structure of Actin Filaments
Actin filaments consist of globular actin (G-actin) subunits that polymerize into long, filaments that are parallel and helical. This polymerised structure is known as filamentous actin (F-actin). The filament has a repeating units which are of 37 nm size, and each G-actin subunit is 5.5 nm in diameter. This polymerization of G-actin into F-actin results in polarized structures with distinct “barbed” and “pointed” ends. These ends can elongate or shorten by the addition or removal of G-actin subunits at either end of the filament.
Some of the key structural properties of actin are as follows:
- Composition of the subunits: G-actin is the subunit that polymerise into F-actin
- Polarity: They are polar in nature, with separate barbed (or positive) and pointed (or negative) ends.
- Helical Structure: The arrangement of G actin subunits causes actin filaments to form a helix.
- Binding Sites: They have binding sites for several regulatory proteins, affecting their stability and dynamics.
Actin Filaments
Actin filaments are microscopic, filamentous structures present in the cytoskeleton. Actin filaments function in cell movement, providing structural support, and facilitating cellular processes such as cytokinesis and cell division. These filaments are dynamic polymers made up of actin protein subunits that create complex networks within cells. In this article, we will look at the structure, function, and dynamics of actin filaments and how they affect cellular functions.
Table of Content
- What is Actin Filament?
- Structure of Actin Filaments
- Dynamics of Actin Filament
- Comparison Among Different Actin Binding Proteins
- What are the Cellular Processes of Actin?
- Functions of Actin Filaments
- Difference Between Actin Filaments and Microtubules