In molecular biology the FYVE zinc finger domain is named after the four cysteine-rich proteins: Fab 1 (yeast orthologue of PIKfyve), YOTB, Vac 1 (vesicle transport protein), and EEA1, in which it has been found.

FYVE domains bind phosphatidylinositol 3-phosphate,[2] in a way dependent on its metal ion coordination and basic amino acids.

The FYVE domain inserts into cell membranes in a pH-dependent manner.

[3] The FYVE domain has been connected to vacuolar protein sorting and endosome function.

[4] The FYVE domain is composed of two small beta hairpins (or zinc knuckles) followed by an alpha helix.