Difference between revisions of "Part:BBa K1230004"

Latest revision as of 22:07, 5 October 2013

MarA Generator

The MarA protein acts as a transcriptional activator in E. coli. It allows the expression of the acrAB and tolC operons, which activate the AcrAB-TolC efflux pump, a mechanism that has been related with resistance to organic solvents, dyes, detergents, antibiotics such as chloramphenicol, tetracycline, novobiocin, erythromycin, fusidic acid and cloxacillin, as well as to cationic antimicrobial peptides, such as LL-37, HNP-2 and HBD-1.

This composite part allows MarA expression in presence of IPTG, by using the LacI promoter and the RBS based on Elowitz repressilator (Part BBa_J04500)

Characterization

We were able to characterise this part, since we found a measurable phenotype (kanamycin resistance).

We also characterised it using Kanamycin �Minimum Inhibitory Concentration� (MIC) finding a MIC with MarA overexpression: 5 µg/ml and a wild-type MIC: 1 µg/ml

A test was performed with three different antibiotics and different IPTG concentrations. The part seems to make the host sensible to Tetracyclin (maybe because it's on Cm plasmid, and both antibiotics act on similar ways), it seems not to have an effect on Ampicilin and it shows a relevant effect with Kanamycin. Which is further explored in the next figure.

Sequence and Features