HUH-tag

Generic HUH endonuclease binding to single-stranded DNA.

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]

  1. ^ Chandler, Michael; de la Cruz, Fernando; Dyda, Fred; Hickman, Alison B.; Moncalian, Gabriel; Ton-Hoang, Bao (2013-07-08). "Breaking and joining single-stranded DNA: the HUH endonuclease superfamily". Nature Reviews Microbiology. 11 (8): 525–538. doi:10.1038/nrmicro3067. ISSN 1740-1526. PMC 6493337. PMID 23832240.
  2. ^ Lovendahl, Klaus N.; Hayward, Amanda N.; Gordon, Wendy R. (2017-05-24). "Sequence-Directed Covalent Protein–DNA Linkages in a Single Step Using HUH-Tags". Journal of the American Chemical Society. 139 (20): 7030–7035. doi:10.1021/jacs.7b02572. ISSN 0002-7863. PMC 5517037. PMID 28481515.
  3. ^ Koonin EV, Dolja VV, Krupovic M, Varsani A, Wolf YI, Yutin N, Zerbini M, Kuhn JH (18 October 2019). "Create a megataxonomic framework, filling all principal taxonomic ranks, for ssDNA viruses" (docx). International Committee on Taxonomy of Viruses. Retrieved 27 May 2020.