Difference between revisions of "Part:BBa K833012"

Revision as of 22:34, 3 October 2012

Lactate sensor derived from the MglB protein from E. coli

This part is a periplasmic lactate sensor derived from site directed mutagenesis of the E. coli MglB protein to create the lactate sensor described by Looger et al. (Looger, LL. et al., Computational design of receptor and sensor proteins with novel functions (Nature 2003). The MglB gene was mutated at the 7 sites reported by Looger et al., (Y10K, D14K, N91K, K92L, H152M, D154H, R158K, W183K, D236A and N256D) by proper primer design and use of the Strategene Multi Site-directed Mutagenesis Kit and protocol. D Due to the multiple mutations, two rounds of mutagenesis were necessary to incorporate all mutations, and several colonies had to be sequenced after each round in order to identify colonies which contained all of the mutations.

This sensor interacts with the Trz fusion protein (iGEM part Bba_J58009) when it binds lactate. The Kd (2 uM) is within the physiological range of lactate concentrations for many cell growth conditions. Trz is a Trg-EnvZ fusion which phosphorylates OmpC when activated. A GFP-based OmpC reporter is available in the iGEM registry (iGEM part BBa_K116503). The reporter we are using is a lacZ reporter, which gives a 4X induction with 100uM L-lactate.

Sequence and Features