A mosaic protein is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

that is made up of different

protein domain In molecular biology, a protein domain is a region of a protein's polypeptide chain that is self-stabilizing and that folds independently from the rest. Each domain forms a compact folded three-dimensional structure. Many proteins consist of s ...

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 In the fields of molecular biology and genetics, 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 ge ...

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 (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

. 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 Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

, 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 (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment ( ...

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, in contrast to unicellular organism. All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- ...

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 The adaptive immune system, also known as the acquired immune system, is a subsystem of the immune system that is composed of specialized, systemic cells and pro ...

are injections of weak germ cells into the body that stimulate the body to produce

antibodies An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...

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 desc ...

, 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 * http://what-when-how.com/molecular-biology/mosaic-protein-molecular-biology/ * {{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