Protein-fragment Complementation Assay
Encyclopedia
Protein-fragment complementation assay, or PCA, is a method for the identification of protein
–protein interactions in biological systems. It is used in the field of proteomics
. In the protein-fragment complementation assay, the proteins of interest ("Bait" and "Prey") are covalently linked at the genetic level to incomplete fragments of a third protein (known as the "reporter") and are expressed in vivo, Interaction between the "bait" and the "prey" proteins brings the fragments of the "reporter" protein in close enough proximity to allow them to reform and become the functional reporter protein. Typically enzymes which confer resistance to antibiotics, such as Dihydrofolate reductase
or Beta-lactamase
, or proteins that give colorimetric or fluorescent signals are used. When used in the context of the reconstitution of fluorescent proteins, it is often called the Bimolecular fluorescence complementation assay
.
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
–protein interactions in biological systems. It is used in the field of proteomics
Proteomics
Proteomics is the large-scale study of proteins, particularly their structures and functions. Proteins are vital parts of living organisms, as they are the main components of the physiological metabolic pathways of cells. The term "proteomics" was first coined in 1997 to make an analogy with...
. In the protein-fragment complementation assay, the proteins of interest ("Bait" and "Prey") are covalently linked at the genetic level to incomplete fragments of a third protein (known as the "reporter") and are expressed in vivo, Interaction between the "bait" and the "prey" proteins brings the fragments of the "reporter" protein in close enough proximity to allow them to reform and become the functional reporter protein. Typically enzymes which confer resistance to antibiotics, such as Dihydrofolate reductase
Dihydrofolate reductase
- Function :Dihydrofolate reductase converts dihydrofolate into tetrahydrofolate, a methyl group shuttle required for the de novo synthesis of purines, thymidylic acid, and certain amino acids...
or Beta-lactamase
Beta-lactamase
Beta-lactamases are enzymes produced by some bacteria and are responsible for their resistance to beta-lactam antibiotics like penicillins, cephamycins, and carbapenems . These antibiotics have a common element in their molecular structure: a four-atom ring known as a beta-lactam...
, or proteins that give colorimetric or fluorescent signals are used. When used in the context of the reconstitution of fluorescent proteins, it is often called the Bimolecular fluorescence complementation assay
Bimolecular fluorescence complementation
Bimolecular fluorescence complementation is a technology typically used to validate protein interactions. It is based on the association of fluorescent protein fragments that are attached to components of the same macromolecular complex...
.
External links
- Protein–Fragment Complementation Assays: A General Strategy for the in vivo Detection of Protein-Protein Interactions – a study in the Journal of Biomolecular Techniques.