The I/LWEQ domain is a ~250-residue actin-binding module that is found in the C termini of functionally diverse proteins from yeast to mammals. The I/LWEQ domain contains four conserved blocks and has been named after the conserved initial residues of blocks 1-4. The I/LWEQ domain is generally found near the C terminus and in association with other domains, such as FERM or ENTH. The I/LWEQ domain … expand

The I/LWEQ domain is a ~250-residue actin-binding module that is found in the C termini of functionally diverse proteins from yeast to mammals. The I/LWEQ domain contains four conserved blocks and has been named after the conserved initial residues of blocks 1-4. The I/LWEQ domain is generally found near the C terminus and in association with other domains, such as FERM or ENTH. The I/LWEQ domain has been shown to bind to F-actin and to bundle actin filaments [ PUBMED:9159132 PUBMED:10581178 PUBMED:16415883 ].

The I/LWEQ domain contains a proteolysis resistant-core that has an all-α-helical structure composed of five long down-up-down-up-down antiparallelhelices connected by short loops and one short connecting α helix arranged in a progressive topology. The proteolysis-resistant core isfollowed by a C-terminal latch region that adopts an α-helical conformation. The latch region can mediate oligomerization of I/LWEQ domains,possibly as dimers, and this seems to enhance the F-actin-binding ability of the proteolysis-resistant core [ PUBMED:16415883 ].

It's worth noting that the I/LWEQ domain has also been called the talin-HIP1/R/Slap2p actin- tethering C-terminal homology (THATCH) domain (HIP1/R/Slap2p denotes similarity of Slap2p to HIP1 and HIP1R) [ PUBMED:16415883 ].