This is a family of Poxviridae metalloendopeptidases. The members were often originally named as G1 proteins. The family carries three zinc-binding ligands and a catalytic glutamate. The first two zinc ligands are histidine residues, found together with the catalytic glutamate in a HXXEH motif, an inverse of the classical metallopeptidase motif, HEXXH. The third zinc ligand is a glutamate C-terminal to the HXXEH motif within a motif ELENEY (see MEROPS).
Jiyao W et al.(2023). "The conserved domain database in 2023.",