A mosaic protein is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

that is made up of different

protein domain In molecular biology, a protein domain is a region of a protein's Peptide, polypeptide chain that is self-stabilizing and that Protein folding, folds independently from the rest. Each domain forms a compact folded Protein tertiary structure, thre ...

s, giving the protein multiple functions. These proteins have quaternary structures, as they are made up of multiple tertiary structured protein domains. Protein domains can combine to form different types of proteins, creating a diversity of proteins. These domains are spread throughout the

genome A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...

because they are mobile, which is why some domains can be found in a variety of proteins, even though they are seemingly unrelated. This also allows the domains to fold independently, and so they don't become deformed and unfolded in a new environment. Whereas many proteins are encoded by a single gene, many others get peptide chains from several genes; it is the nature of mosaic proteins that they are always polygenic.

Development

All proteins are transcribed and produced from blueprints in the cell, called

genes In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

. Mosaic proteins can be made when two adjacent genes are transcribed together and are therefore made into the same protein. This can benefit the protein because it makes the protein more stable and gives the protein a more complex function. For example, if the protein is an

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

, it will be able to act more efficiently with its substrates. Additionally, these proteins are most utilized outside of the

cell membrane The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extr ...

or on the outer side of membrane proteins. This suggests that these multifunctional proteins played a part in the development of

multicellular organisms A multicellular organism is an organism that consists of more than one cell, unlike unicellular organisms. All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- and pa ...

Examples

There are many studies comparing different mosaic proteins and their functional domains, trying to understand protein families and the overall functions of different proteins. For example, SpCRL and SpCRS proteins in sea urchins have a variety of functional domains that are also found within other proteins in the animal. By making comparisons, scientists can understand the complex roles these proteins play. Also, scientists are using the concept of mosaic proteins to improve vaccine function.

Vaccines A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified. A vaccine typically contains an ag ...

are injections of weak germs into the body that stimulate the body to produce

antibodies An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as bacteria and viruses, including those that caus ...

specific to that germ. This ensures that the body will build an

immunity Immunity may refer to: Medicine * Immunity (medical), resistance of an organism to infection or disease * ''Immunity'' (journal), a scientific journal published by Cell Press Biology * Immune system Engineering * Radiofrequence immunity ...

, and that next time the germ is introduced, it will be more equipped to fight it off. Mosaic proteins of the germs can be designed in order to maximize antibody production and quality.

References

External links

* http://www.hiv.lanl.gov/content/sequence/MOSAIC/mosaic_explanation.html * {{cite journal , pmid=9157966 , volume=17 , issue=5 , title=A novel mosaic protein containing LDL receptor elements is highly conserved in humans and chickens , year=1997 , journal=Arterioscler. Thromb. Vasc. Biol. , pages=996–1002 , last1 = Mörwald , first1 = S , last2 = Yamazaki , first2 = H , last3 = Bujo , first3 = H , last4 = Kusunoki , first4 = J , last5 = Kanaki , first5 = T , last6 = Seimiya , first6 = K , last7 = Morisaki , first7 = N , last8 = Nimpf , first8 = J , last9 = Schneider , first9 = WJ , last10 = Saito , first10 = Y , doi=10.1161/01.atv.17.5.996 * http://www.nature.com/icb/journal/v71/n3/abs/icb199324a.html Proteins

Development

Examples

See also

References

External links