Part:BBa_K1039021

Bxb1 integrase (BBa_K1039003) and lacI repressor (BBa_Q04121) are under the constitutive strong promoter BBa_J23119. Key (BBa_I714036) and Bxb1 RDF (BBa_K1039006) are under the lac inducible promoter BBa_R0011.

Bxb1 integrase (BBa_K1039003) and recombination directionality factor (RDF) (BBa_K1039006) with ribosome binding sites associated with the cis-repressive RNA “lock” (BBa_J01010), so translation is inhibited. The trans-activating RNA “key” (BBa_I714036) can displace the lock and allows translation.

Together, Bxb1 integrase and RDF (BBa_K1039003 and BBa_K1039006) catalyze site-specific recombination between Bxb1 attR and attL sites (Bba_K1039033 and Bba_K1039034)

They will also allow flipping of Bxb1 invertible promoter switches BBa_K1039004 and BBa_K1039004 from RL state to PB state.

Lock and key regulate BXB1 integrase and BRDF expression. BXB1 integrase and BRDF’s expression is blocked by lock. Key expression is controlled by a lacI repressor, upon IPTG addition to the media, key will be expressed, which then unlocks BXB1 integrase and BRDF.