Conversion of a telomere resolvase into a Cre-like site-specific recombinase
Hairpin telomere resolvases are a unique family of enzymes involved in producing the hairpin (hp) telomeres of bacterial organisms and phages that possess linear DNA's terminated by hp telomeres. The hp telomeres help to overcome the end-replication problem faced by linear DNAs and are generated from replicated intermediates of the linear DNAs. The telomere resolvases employ a reaction mechanism and catalytic domain related to that of the type IB topoisomerases and tyrosine recombinases. ResT, the telomere resolvase from Borrelia burgdorferi, under certain reaction conditions, has been shown to promote site-specific recombination between replicated telomere junctions (rTels) to produce a Holliday junction intermediate in a reaction strikingly similar to that promoted by tyrosine recombinases.