Epiregulin
Encyclopedia
Epiregulin is a protein
that in humans is encoded by the EREG gene
.
contains approximately 30 percent of β-sheet
in the strand. Some of the residues form loops and turns due to the hydrogen bonding. The percentage of β-sheet in epiregulin depends on the domain
and the secondary structures that they occupy. The polymeric molecules of epiregulin has the formula weight of 5280.1 g/mol with a polypeptide(L), a polymer type.
Structural motifs in most proteins have typical connections in an all β motif. Meaning that the polypeptide chains do not make a crossover connection or in so far as this type of connection has not been observed. Epiregulin is one of the proteins that occupies a typical connection in all β motif. Furthermore, as the structure of epiregulin forms a chain in an all β motif, it also forms β hairpin structural motif
. A β hairpin is when the two adjacent anti-parallel β strands connected by a β-turn.
family. Epiregulin can function as a ligand of epidermal growth factor receptor
(EGFR), as well as a ligand of most members of the ERBB
(v-erb-b2 oncogene homolog) family of tyrosine-kinase receptor
s. The secondary structure at the C-terminus epiregulin is different from other epidermal growth factor family ligands because of the lack of hydrogen bonds. The structural difference at the C-terminus may provide an explanation for the reduced binding affinity of epiregulin to the ERBB receptors.
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...
that in humans is encoded by the EREG gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
.
Structure
Epiregulin consists of 46 amino acid residues. Its secondary structureSecondary structure
In biochemistry and structural biology, secondary structure is the general three-dimensional form of local segments of biopolymers such as proteins and nucleic acids...
contains approximately 30 percent of β-sheet
Beta sheet
The β sheet is the second form of regular secondary structure in proteins, only somewhat less common than the alpha helix. Beta sheets consist of beta strands connected laterally by at least two or three backbone hydrogen bonds, forming a generally twisted, pleated sheet...
in the strand. Some of the residues form loops and turns due to the hydrogen bonding. The percentage of β-sheet in epiregulin depends on the domain
Domain
-General:*Territory , a non-sovereign geographic area which has come under the authority of another government*Public domain, a body of works and knowledge without proprietary interest...
and the secondary structures that they occupy. The polymeric molecules of epiregulin has the formula weight of 5280.1 g/mol with a polypeptide(L), a polymer type.
Structural motifs in most proteins have typical connections in an all β motif. Meaning that the polypeptide chains do not make a crossover connection or in so far as this type of connection has not been observed. Epiregulin is one of the proteins that occupies a typical connection in all β motif. Furthermore, as the structure of epiregulin forms a chain in an all β motif, it also forms β hairpin structural motif
Structural motif
In a chain-like biological molecule, such as a protein or nucleic acid, a structural motif is a supersecondary structure, which appears also in a variety of other molecules...
. A β hairpin is when the two adjacent anti-parallel β strands connected by a β-turn.
Function
Epiregulin is a member of the epidermal growth factorEpidermal growth factor
Epidermal growth factor or EGF is a growth factor that plays an important role in the regulation of cell growth, proliferation, and differentiation by binding to its receptor EGFR...
family. Epiregulin can function as a ligand of epidermal growth factor receptor
Epidermal growth factor receptor
The epidermal growth factor receptor is the cell-surface receptor for members of the epidermal growth factor family of extracellular protein ligands...
(EGFR), as well as a ligand of most members of the ERBB
ErbB
The ErbB protein family or epidermal growth factor receptor family is a family of four structurally related receptor tyrosine kinases. The gene symbol, ErbB, is derived from the name of a viral oncogene to which these receptors are homologous: Erythroblastic Leukemia Viral Oncogene...
(v-erb-b2 oncogene homolog) family of tyrosine-kinase receptor
Receptor tyrosine kinase
Receptor tyrosine kinases s are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Of the 90 unique tyrosine kinase genes identified in the human genome, 58 encode receptor tyrosine kinase proteins....
s. The secondary structure at the C-terminus epiregulin is different from other epidermal growth factor family ligands because of the lack of hydrogen bonds. The structural difference at the C-terminus may provide an explanation for the reduced binding affinity of epiregulin to the ERBB receptors.