Difference between revisions of "Part:BBa K2448038"

Latest revision as of 21:48, 31 October 2017

pSB1C3 LacIq

This part is the pSB1C3 backbone vector with a built-in LacIq sequence provided with the BBa_J04450 reporter.

Usage and Biology

pSB1C3 is a well know high copy number plasmid (RFC [10]) carrying a chloramphenicol resistance, a pMB1 replication origin (100-300 copy per cell) and highly efficient terminators bracketing its suffix and prefix regions thus preventing transcription from part sequences out into the vector.

pSB1C3 is the iGEM workhorse for gene expression. However, when it comes to the of use LacI regulated promoters, very frequently significant leakage is observe due to its important copy number, which leads to important regulation problems. This issue can be addressed either by including the LacI coding sequence into the construct or by using only LacI overexpressing cells.

To facilitate further use of this plasmid, we designed a pSB1C3 with a built-in LacI coding sequence under the control of a mutated version of its own natural promoter known as LacIq. This is a single C to T change at −35 of the promoter region of LacI which leads to a 10-fold increase in LacI expression [1].

The LacIq has been recovered from the pQLinkH plasmid [2] and directly inserted between the origin of replication and the VR primer of pSB1C3 thus improving the general regulation of LacI related parts. This part is provided with a reporter (BBa_J04450).

A relevant application of this part would be the use with it with our Universal Biosensing Chassis (BBa_K2448023 and BBa_K2448024) to build a transcription factor based biosensor finely regulated.

Sequence and Features