HUH-tag
From Wikipedia, the free encyclopedia
HUH endonucleases (HUH-tags) are sequence-specific single-stranded DNA (ssDNA) binding proteins originating from numerous species of bacteria and viruses.[1] Viral HUH endonucleases are involved in initiating rolling circle replication while ones of bacterial origin initiate bacterial conjugation. In biotechnology, they can be used to create protein-DNA linkages,[2] akin to other methods such as SNAP-tag. In doing so, they create a 5' covalent bond between the ssDNA and the protein. HUH endonucleases can be fused with other proteins or used as protein tags.
The name HUH stands for "histidine-hydrophobic-histidine," referring to the three amino acids at the active site of the endonuclease. Some DNA viruses code for an HUH endonuclease which initiates rolling circle replication of the viral genome, and this process defines the realm Monodnaviria.[3]