Part:BBa_K4129103

The synthetic transcription factor, FunsTF05 (LexA-LL-Hmox1-VP16-SV40)

FunsTF05 is a synthetic transcription factor (sTF). FunsTF05 should initiate the transcription through the 6xLexO minimal promoter. This sTF is the sensing part of the biosensor.

FunsTF05 is a fusion protein consisting of the DNA-binding domain: lexA, ligand sensing domain: Hmox1, transactivation domain; VP16 and the nuclear localization signal (NLS) SV40. The linker between LexA and Hmox1 was a longer version (Ottoz et. al (2014) compared to sBAD (Castaño-Cerezo et. al (2020)).

LexA is a repressor that regulates the SOS response in E. coli (Radman. 1975). LexA binds to a specific DNA motif, lexO (Erill. et al (2003)), and it is the DNA binding domain that interacts with LexO that is used in FunsTF05. Hmox1 is the human heme oxygenase 1, which can cleave heme. This function is not of our interest, but it was shown that furfural binds to hmox1. Viral Protein 16 (VP16) from herpes simplex virus type 1 is a transcription factor that uses a transactivation domain to recruit the RNA polymerase II.The NLS SV40 is a small peptide sequence of PKKKRKV that enables transport of the protein to the nucleus (Garcia-Bustos et. al (1991)).

Figure 1: Aspergillus. niger grown on minimal media (MM), MM with 2 mM benzoic acid and MM with 0.6 g/L furfural .