BpuJI is a restriction endonuclease which recognises the asymmetric sequence 5'-CCCGT and cuts at multiple sites in the surrounding area of the target sequence. This family of proteins is the N terminal domain of BpuJI which has DNA recognition functions. The recognition domain has two subdomains D1 and D2. The recognition of the target sequence occurs through major groove contacts of amino acids on the helix-turn-helix region and the N-terminal arm [1].

1: The recognition domain of the BpuJI restriction endonuclease in complex with cognate DNA at 1.3-A resolution. Sukackaite R, Grazulis S, Bochtler M, Siksnys V; J Mol Biol. 2008;378:1084-1093. PMID:18433771