Difference between revisions of "Part:BBa K197026"

Latest revision as of 04:49, 22 October 2009

INP-Repeats

This is used as a spacer for cell surface display. It is derived from the inaZ gene responsible for ice nucleation by Pseudomonas syringae but includes only the repeat domains from the protein. These repeats are believed to encode a beta-solenoid-type fold and are responsible for the ice-nucleation phenotype of cells expressing full-length inaZ. We have observed that including these repeats as a spacer element can improve the display of proteins.

This part is a cell-surface displayer spacer part. A spacer is used to improve the display of passenger domains.

For successful cell surface display of proteins, there must be an effective protein localization mechanism. Gram-negative bacteria such as E. Coli have two membranes, which present a problem for transporting proteins synthesized in the cytoplasm to the outside of the cell. Various transport schemes exist in gram-negative bacteria to effectively localize proteins to the outermembrane. The most common schemes are TypeI, TypeIII, and TypeV secretion.

The heat map above points to an interesting trend made clear by the streptavidin and mgfp-5 data. Although all constructs contain short linkers between the displayers and passengers, the inclusion of spacer elements for both systems appears to enhance functional surface display of the passengers. Moreover, the identity of the spacer element is an important parameter determining display efficiency. There is an increase in functional display when the INP repeats spacer is added between the displayers and the strep tag as is seen in the increase in lighter blocks in the map. This trend is especially evident in the mgfp data in which there are several weak signals (many dark blocks in the map) for mgfp displayed on its own. With the addition of several spacer elements, a significant general increase in signal for almost 100% of the systems is observed.
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Sequence and Features