ENTH domain

SCOP2		1edu / SCOPe / SUPFAM
OPM superfamily	38
OPM protein	1h0a
CDD	cd03571
Available protein structures: Pfam   structures / ECOD   PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

The epsin N-terminal homology (ENTH) domain is a

machinery.

This domain is approximately 150 amino acids in length and is always found located at the N-termini of proteins. The domain forms a compact globular structure, composed of nine alpha-helices connected by loops of varying length. The general topology is determined by three helical hairpins that are stacked consecutively with a right hand twist.^[2] An N-terminal helix folds back, forming a deep basic groove that forms the binding pocket for the Ins(1,4,5)P3 ligand.^[1] The lipid ligand is coordinated by residues from surrounding alpha-helices and all three phosphates are multiply coordinated.

Proteins containing this domain have been found to bind

content. Epsin binding to membranes facilitates their deformation by insertion of the N-terminal helix into the inner leaflet of the bilayer, pushing the head groups apart. This would reduce the energy needed to curve the membrane into a vesicle, making it easier for the clathrin cage to fix and stabilise the curved membrane. This points to a pioneering role for epsin in vesicle budding, as it provides both a driving force and a link between membrane invagination and clathrin polymerisation.

In particular, epsin-1 shows specificity for the membrane glycophospholipid

polymerisation.

The N-terminal alpha-helix of this domain is hydrophobic and inserts into the membrane like a wedge and helps to drive membrane curvature.

Human proteins containing this domain

;

References

External links

• Endocytosis.org entry on epsin

Further reading

Ford MG, Mills IG, Peter BJ, et al. (September 2002). "Curvature of clathrin-coated pits driven by epsin". Nature. 419 (6905): 361–6.

S2CID 4372368

.