InterPro domain: IPR014352

This superfamily represents a structural domain with a core structure consisting of a 3-helical closed bundle with a left-handed twist, in an up-and-down arrangement. This structural motif occurs as subdomain 2 within FERM domains, as well as in acyl-CoA-binding proteins. The FERM domain (band F ezrin-radixin-moesin homology domains) has such a structure, acting as a common membrane-binding module involved in localising proteins to the plasma membrane [ 1 ]. Proteins containing FERM include cytoskeletal proteins such as erythrocyte membrane protein 4.1R, talin, and the ezrin-radixin-moesin protein family, as well as several protein tyrosine kinases and phosphatases, and the neurofibromatosis 2 tumour suppressor protein merlin. The ezrin-radixin-moesin protein family function is to crosslink the actin filaments of cytoskeletal structures to the plasma membrane.

In addition, acyl-CoA-binding protein (ACBP) contains a domain with a similar 3-helical bundle structure. ACBP plays an important role in fatty acid metabolism, maintaining a pool of fatty acyl-CoA molecules in the cell [ 2 ].

1. Structure of the ERM protein moesin reveals the FERM domain fold masked by an extended actin binding tail domain. Cell 101, 259-70
2. Binding site differences revealed by crystal structures of Plasmodium falciparum and bovine acyl-CoA binding protein. J. Mol. Biol. 309, 181-92