Member database | SUPERFAMILY |
SUPERFAMILY type | homologous superfamily |
Description Imported from IPR044925
His-Me finger is a diverse superfamily of endonuclease proteins present in all forms of life and involved in various cellular processes. The structural core of this group of proteins consists of a β-hairpin followed by an α-helix, forming a binding site for a single catalytic metal ion. The His-Me finger is thought to be suited for efficient, nonspecific DNA cleavage. The term 'His-Me' refers to a nearly invariant catalytic histidine (His) residue and a bound metal ion (Me). His-Me finger-containing proteins are commonly called HNH nucleases. HNH sequence motif consists of the central, nearly invariant, catalytic histidine at the C terminus of the first β-strand (HNH), an asparagine (HNH) in the extensive loop connecting the two β-strands known as the ω-loop (16)-and a histidine (HNH) in the core α-helix. This second histidine is often substituted by an asparagine, which, in most cases, is the only residue that directly binds the metal ion
[1].