Caulobacter Crescentus: A New Expression and Display System

A novel protein and peptide expression and display system utilizing the S-layer of Caulobacter crescentus

Advantages

C. Crescentus protein Secretion system:

Production is easily scalable, inexpensive and contains no animal or plant proteins.
Secreted proteins can be easily retrieved
Large quantities of a wide range of proteins (2-70 KDa) can be produced; approximately 500mg/L of batch culture, typically 100mg/L for successful clones.
The endotoxin potential of the C. crescentus LPS is approximately 1000 times lower than E. coli.
Cloning vehicle is a single high copy number vector that replicates in Caulobacter as well as E. coli cloning strains.

C. Crescentus protein Display system:

Display of peptides from 10-300 amino acids in length has acheiveable
Multiple peptides/proteins can be displayed on the same bacterium.
The genetics and biochemistry of C. crescentus are well established, allowing easy engineering of the system.
Caulobacters are detecteable and can be used in a Fluorescence Activated Cell Sorter.

Technology Details

Inventors at The University of British Columbia have developed a novel protein expression and display system using Caulobacter crescentus, a harmless gram-negative, non-pathogenic, aerobic bacteria which produces and secretes a single expressed protein that assembles on its outer surface, forming a two-dimensional paracrystalline array or S-layer.  The S-layer represents approximately 10% of the total cellular protein and is secreted by a flexible Type I secretion mechanism.  Management of this system results in the scalable, inexpensive secretion of recombinant proteins (via fusion with a C-terminal secretion signal) or display of peptides or proteins on the cell surface (via insertion into the complete S-layer gene sequence).