F-actin capping protein
In molecular biology, the F-actin capping protein is a protein complex which binds in a calcium-independent manner to the fast-growing ends of actin filaments (barbed end), thereby blocking the exchange of subunits at these ends. Unlike gelsolin and severin this protein does not sever actin filaments. The F-actin capping protein is a heterodimer composed of two unrelated subunits: alpha and beta. Neither of the subunits shows sequence similarity to other filament-capping proteins. The alpha subunit is a protein of about 268 to 286 amino acid residues and the beta subunit is approximately 280 amino acids, their sequences are well conserved in eukaryotic species.
| F-actin capping protein alpha subunit | |||||||||
|---|---|---|---|---|---|---|---|---|---|
solution nmr structure of s100b bound to the high-affinity target peptide trtk-12 | |||||||||
| Identifiers | |||||||||
| Symbol | F-actin_cap_A | ||||||||
| Pfam | PF01267 | ||||||||
| InterPro | IPR018315 | ||||||||
| PROSITE | PDOC00609 | ||||||||
| SCOP2 | 1izn / SCOPe / SUPFAM | ||||||||
| |||||||||
| F-actin capping protein, beta subunit | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | F_actin_cap_B | ||||||||
| Pfam | PF01115 | ||||||||
| InterPro | IPR001698 | ||||||||
| PROSITE | PDOC00203 | ||||||||
| SCOP2 | 1izn / SCOPe / SUPFAM | ||||||||
| |||||||||
The actin filament system, a prominent part of the cytoskeleton in eukaryotic cells, is both a static structure and a dynamic network that can undergo rearrangements: it is thought to be involved in processes such as cell movement and phagocytosis, as well as muscle contraction.