Integrasegenet

Integrasegenet is a term used to denote a gene encoding an integrase enzyme, a type of recombinase that mediates site-specific DNA recombination. Integrases enable the insertion or excision of mobile genetic elements, such as bacteriophage genomes, transposons, and retroelements, into and out of host chromosomes. The concept encompasses both naturally occurring integrase genes found in diverse organisms and domesticated or repurposed versions embedded in host genomes.

Integrases are broadly classified into two main families: tyrosine recombinases and serine recombinases. Both catalyze strand exchange between defined DNA attachment sites, but they differ in catalytic residues, reaction pathways, and regulatory requirements. In many systems, the enzyme recognizes short attachment sites such as attP/attB or related sequences and coordinates integration with host factors. Directionality, efficiency, and site choice can be modulated by auxiliary proteins, phage-encoded factors, or host proteins that influence DNA conformation.

In biology and biotechnology, integrases play central roles in genome integration during viral replication and horizontal gene transfer, as well as in engineered genome modification strategies. HIV integrase is a well-studied example, and integrase inhibitors are important antiretroviral drugs. Beyond therapeutics, integrases are exploited in gene therapy and synthetic biology to achieve stable, targeted insertion of genetic payloads. The distribution of integrase genes spans bacteria, archaea, and eukaryotic-associated mobile elements, reflecting a long evolutionary history of genome remodeling and element mobility.