Difference between revisions of "Part:BBa K1583200"

Revision as of 14:16, 17 September 2015

Low constitutive promoter + CsgC

CsgC is positively involved in the extracellular aggregation of CsgA into amyloid nanowires (curli assembly) in E.coli. Inside the cell, it prevents the premature aggregation and thus the formation of nanowires in the cytosol. Constructs with different promoter strenghts were designed to investigate the impact of chaperone expression levels on the nanowire self-assembly process.

Sequence and Features

A bacterial biofilm consists up to 80% of amyloid nanowires. These nanowires are often called curlis and they are made from a protein monomer called CsgA. Hundreds and thousands of these monomers aggregate to a form a nanowire of up to several micrometers in length. The curli nucleation process to is induced by the membrane protein CsgB, which functions as a cellular anchor via which the nanowire attaches to the cell.

CsgC has the function to prevent intracellular aggregation of CsgA and thus the formation of nanowires within the cell. Along with other proteins
(CsgE, CsgF, CsgG) CsgC is an important parameter in providing mature CsgA in the extracellular space in the most efficient way.

But which is the most efficient way?

By creating devices in which the protein CsgC is constitutively expressed at different levels using three different promoter strengths, we were hoping to identify the expression level corresponding to the strongest biofilm.

Relative promoter strengths [au]:

J23110: 844

J23118: 1429

J23100: 2547

This device was intended as a platform for the further addition of CsgE, CsgF and CsgG genes to investigate their impact on the amount of available, mature, extracellular CsgA.