We have identified a ∼140 amino acid domain
that is shared by a variety of proteins in budding and
fission yeast, nematode, rat, mouse, frog, oat, and man.
Typically, this domain is located within 20 residues of
the N-terminus of the various proteins. The percent identity
among the domains in the 12 proteins ranges from 42 to
93%, with 16 absolutely conserved residues: N-x11–13-V-x2-A-T-x34–36-R-x7–8-W-R-x3-K-x12-G-x-E-x15-L-x11–12-D-x-G-R-x11-D-x7-R.
Even though these proteins share little beyond their segment
of homology, data are emerging that several of the proteins
are involved in endocytosis and or regulation of cytoskeletal
organization. We have named this protein segment the ENTH
domain, for Epsin N-terminal
Homology domain, and hypothesize that it is a
candidate for binding specific ligands and/or enzymatic
activity in the cell.