Difference between revisions of "Part:BBa K1642011"

Revision as of 14:19, 27 October 2016

Expression of Halorhodopsin under the control of Pdrak 600px|thumb|left|Figure1. Control mechanism of Pdark. (a) Under natural light, the green light component induces phosphorylation of CcaR, and the binding of it to Pdark prevents the binding of RNA polymerase, thus inhibiting expression of halorhodopsin. (b) Under darkness, RNA Polymerase binds to Pdark as it does in E.coli and initiate the transcription of halorhodopsin. Pdark-HR is a plasmid used to test whether the protein halorhodopsin under the control of P dark works as we expect.

Up and Down are sequences used for homologous recombination.

Pdark(BBa_K1026009) is a “dark-sensing” promoter combines PcpcG2 and a constitutive promoter from E.coli. Pdark contains binding site of CcaR in PcpcG2, which overlaps with the binding site of RNA polymerase. Therefore when phosphorylated CcaR binds to it, the binding of RNA polymerase to Pdark will be blocked and transcription can’t be initiated.

RBS is the RNA binding site, which will hopefully increase the expression level of HR.

Halorhodopsin (HR) proteins are light-driven inward-directed chloride pumps from halobacteria. We use this as our biodesalination driver which confers cyanobacteria the ability to absorb chloride to a significant degree.

Terminator is the transcription terminator for the E.coli RNA polymerase.

Sequence and Features