Like all integrin subunits, β7 is a highly flexible, membrane-bound, extracellular protein that must pair with an α subunit for stability. The molecule's flexibility allows it to dynamically regulate its affinity for ligand through conformational changes.[4] Beginning with the apical end of the protein, farthest from the cell membrane, the β7 is composed of a head and upper legs, collectively known as the headpiece, lower legs, a transmembrane domain and a cytoplasmic tail. The top of the head is the I-like domain, sometimes called the βI domain, which, in combination with the α subunit, binds ligand. Just below this is the hybrid domain, a portion of which is N-terminal to the I-like domain. Below the hybrid domain is the PSI domain, which completes the headpiece. The lower legs consist of EGF domains 1-4 and the β tail domain. Finally there is a transmembrane domain, and the C-terminal cytoplasmic tail.[5]
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↑Rietzler M, Bittner M, Kolanus W, Schuster A, Holzmann B (Oct 1998). "The human WD repeat protein WAIT-1 specifically interacts with the cytoplasmic tails of beta7-integrins". The Journal of Biological Chemistry. 273 (42): 27459–66. doi:10.1074/jbc.273.42.27459. PMID9765275.
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