Part:BBa_K143033

LacI (Lva^-, N-terminal deletion) regulatory protein

LacI is a regulatory protein responsible for the repression of many catabolite genes. Transcription is regulated by proteins which bind operator sequences around the transcription start site. These proteins can positively affect transcription (activators) or negatively affect transcription (reppresors). Some repressor proteins can be inactivted however by addition of an inducer, such as IPTG or certain sugars.

LacI if the regulator protein for the lactose operon in E.coli and the hyper-spank protein of B. subtilis#1(BBaK143015) and is responsible for ensuring that in the absence of lactose (or IPTG) that there is no expression trough these promoter. LacI is not endogenous to B. subtilis, so LacI will need to be expressed in the host in order for the hyper-spank promoter to be regulated. In the presence of IPTG or lactose, the LacI tetramer is unable to bind DNA and so transcription resumes.

This version of LacI lacks a Lva degradation tag and has a small(3 amino acid) N-terminal deletion relative to the current registry LacI (BBa_C0012