This is the N-terminal domain (K2-N) of Kindlin-2 protein present in Homo sapiens. Kindlin-2 is a regulator for heterodimeric integrin adhesion receptors promotes integrin activation. Activation depends on binding of the N-terminal domain to the integrin beta cytoplasmic tail (CT), which disrupts the receptors association with alpha-CT and triggers the conformational transitions in the receptor. K2-N contains a conserved positively charged surface that binds to membrane enriched with negatively charged phosphatidylinositol-(4,5)-bisphosphate (PIP2). K2-N is also very similar to the homologous kindlin-1 F0 [1].

1: Membrane binding of the N-terminal ubiquitin-like domain of kindlin-2 is crucial for its regulation of integrin activation. Perera HD, Ma YQ, Yang J, Hirbawi J, Plow EF, Qin J; Structure. 2011;19:1664-1671. PMID:22078565

2: The structure of the N-terminus of kindlin-1: a domain important for alphaiibbeta3 integrin activation. Goult BT, Bouaouina M, Harburger DS, Bate N, Patel B, Anthis NJ, Campbell ID, Calderwood DA, Barsukov IL, Roberts GC, Critchley DR; J Mol Biol. 2009;394:944-956. PMID:19804783