Team:Berkeley Wetlab/Cell Surface Display Parts

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Revision as of 11:43, 19 October 2009

Cell Surface Display Parts

Follow any of the links below for more information about each of the passengers we made.

Streptavidin A tag that binds the protein streptavidin!	Leucine Zippers A structural motif that can allow different cell types to recognize and to bind each other!	Ag4 Peptide A peptide that reduces silver ions to form a silver precipitate!
MGFP-5 A protein used by mussels to stick to rocks. An underwater bio-glue!	Cellulases Enzymes that degrade cellulose!	TypeIII Needle scFv An antibody that binds a motif common to enteropathogenic bacteria!

Displayers: An outmembrane protein that carries another protein through the outermembrane

For successful cell surface display of proteins, there must be an effective protein localization mechanism. Gram-negative bacteria such as E. Coli have inner and outer membranes that 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. In our display systems, we chose a class of outermembrane proteins called autotransporters that localizes proteins via the TypeV secretion mechanism. This system is particular suited for cell surface display because the outermembrane protein (aka displayer) spontaneously inserts into the outermembrane and pulls the protein it is covalently linked to (aka passenger)into the extracellular space. Moreover, autotransporters are capable of pulling through large proteins, such as enzymes and single-chain variable fragments.

As depicted in the diagram above, the autotransporter localization begins with... Many of these systems use the sec pathway to first localize the protein from the cytoplasm to the periplasm, a space between the inner and outermembranes.

azo1653 AtD OprF AtD Cl02365 AtD VtaA11 Hag AtD Pcryo_1225AtD Hia AtD upaG_short espP(beta) ehaB TshA VirG YuaQ AtD AIDA-I AtD Ag43_short

Repeated portion of ice nucleation protein (INP) sequence.

Retrieved from "http://2009.igem.org/Team:Berkeley_Wetlab/Cell_Surface_Display_Parts"

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 An antibody that binds a motif common to enteropathogenic bacteria!<br>
 |}
-* Displayers
+* Displayers: An outmembrane protein that carries another protein through the outermembrane
-Protein localization - The general scheme of protein localization is as shown in the following diagram.
+For successful cell surface display of proteins, there must be an effective protein localization mechanism. Gram-negative bacteria such as E. Coli have inner and outer membranes that 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.
+In our display systems, we chose a class of outermembrane proteins called autotransporters that localizes proteins via the TypeV secretion mechanism. This system is particular suited for cell surface display because the outermembrane protein (aka displayer) spontaneously inserts into the outermembrane and pulls the protein it is covalently linked to (aka passenger)into the extracellular space. Moreover, autotransporters are capable of pulling through large proteins, such as enzymes and single-chain variable fragments.
+As depicted in the diagram above, the autotransporter localization begins with...
+Many of these systems use the sec pathway to first localize the protein from the cytoplasm to the periplasm, a space between the inner and outermembranes.
-Gram-negative bacteria have double membranes that present a problem for protein localization. Several protein transport mechanisms have been evolved to deal with this problem. These mechanisms include TypeI - TypeV secretion.
-In our display systems, we used mainly autotransporters and some circularly permuted proteins. Autotransporters belong to a class of outermembrane proteins that is part of the TypeV secretion system common in many prokaryotic organisms.
 azo1653 AtD