Tre recombinase

Tre recombinase is an experimental enzyme that in lab tests has removed DNA inserted by HIV from infected cells.{{cite journal |first1=Indrani |last1=Sarkar |first2=Ilona |last2=Hauber |first3=Joachim |last3=Hauber |first4=Frank |last4=Buchholz |year=2007 |title=HIV-1 proviral DNA excision using an evolved recombinase |journal=Science |volume=316 |issue=5833 |pages=1912–15 |pmid=17600219 |doi=10.1126/science.1141453 |bibcode=2007Sci...316.1912S |s2cid=2437602 }} Through selective mutation, Cre recombinase which recognizes loxP sites are modified to identify HIV long terminal repeats (loxLTR) instead. As a result, instead of performing Cre-Lox recombination, the new enzyme performs recombination at HIV provirus sites.{{cite journal |title=Highly Significant Antiviral Activity of HIV-1 LTR-Specific Tre-Recombinase in Humanized Mice |first1=Ilona |last1=Hauber |first2=Helga |last2=Hofmann-Sieber |first3=Jan |last3=Chemnitz |display-authors=3 |first4=Danilo |last4=Dubrau |journal=PLOS Pathogens |volume = 9|issue = 9|pages = e1003587|date=September 26, 2013 |doi=10.1371/journal.ppat.1003587 |pmid = 24086129|pmc=3784474 |doi-access=free }}

The structure of Tre in complex with loxLTR has been resolved ({{PDB|5U91}}), allowing for analyzing the roles of individual mutations.{{cite journal |last1=Meinke |first1=G |last2=Karpinski |first2=J |last3=Buchholz |first3=F |last4=Bohm |first4=A |title=Crystal structure of an engineered, HIV-specific recombinase for removal of integrated proviral DNA. |journal=Nucleic Acids Research |date=19 September 2017 |volume=45 |issue=16 |pages=9726–9740 |doi=10.1093/nar/gkx603 |pmid=28934476 |pmc=5766204 |doi-access=free}}