|PROSITE documentation PDOC50021 [for PROSITE entry PS50021]|
A number of actin-binding proteins, including spectrin, α-actinin and fimbrin, contain a 250 amino acid stretch called the actin binding domain (ABD). The ABD has probably arisen from duplication of a domain which is also found in a single copy in a number of other proteins like calponin or the vav proto-oncogene and has been called calponin homology (CH) domain [1,2].
A detailed analysis of the CH domain-containing proteins has shown that they can be divided in three groups :
Each single ABD, comprising two CH domains, is able to bind one actin monomer in the filament. The amino terminal CH domain has the intrinsic ability to bind actin, albeit with lower affinity than the complete ABD, whereas the carboxy terminal CH bind actin extremely weakly or not at all. Nevertheless both CH domains are required for a fully functional ABD; the C-terminal CH domain contributing to the overall stability of the complete ABD through inter-domain helix-helix interactions . Some of the proteins containing a single CH domain also bind to actin, although this has not been shown to be via the single CH domain alone . In addition, the CH domain occurs also in a number of proteins not known to bind actin, a notable example being the vav proto-oncogene.
The resolution of the 3D structure of various CH domains has shown that the conserved core consist of four major α-helices .
Some proteins known to contain a CH-domain are listed below:
August 2017 / Profile and text revised.
PROSITE method (with tools and information) covered by this documentation:
|1||Authors||Stradal T., Kranewitter W., Winder S.J., Gimona M.|
|Title||CH domains revisited.|
|Source||FEBS Lett. 431:134-137(1998).|
|2||Authors||Keep N.H., Norwood F.L., Moores C.A., Winder S.J., Kendrick-Jones J.|
|Title||The 2.0 A structure of the second calponin homology domain from the actin-binding region of the dystrophin homologue utrophin.|
|Source||J. Mol. Biol. 285:1257-1264(1999).|
|3||Authors||Chan S.W., Fowler K.J., Choo K.H.A., Kalitsis P.|
|Title||Spef1, a conserved novel testis protein found in mouse sperm flagella.|
|4||Authors||Wang X., Harimoto K., Liu J., Guo J., Hinshaw S., Chang Z., Wang Z.|
|Title||Spata4 promotes osteoblast differentiation through Erk-activated Runx2 pathway.|
|Source||J. Bone Miner. Res. 26:1964-1973(2011).|
|5||Authors||Schroeder C.M., Vale R.D.|
|Title||Assembly and activation of dynein-dynactin by the cargo adaptor protein Hook3.|
|Source||J. Cell Biol. 214:309-318(2016).|