The following elements are proposed to express the idea of a protein and its composition of subunits with their component, highly ordered polypeptide chains. The concepts of modification and annotation of peptide-specific structures is also included. Protein elements The highest level attributes for a protein is the protein itself and the subunits that make up the protein. The possibility of more than one peptide component exists because of the possibility of editing of a translated mRNA peptide by enzymes within a cell. The various elements that result from this editing are described below as domains.
Peptides are the long chains of amino acid residues that make up a protein subunit.
Peptide chains can be divided up into functional regions, called domains, which may have particular structural or functional attributes. Many gene products are made in a slightly longer form than is present in the mature protein. It is very possible that some domains may overlap. Therefore it is not necessary to enclose the residues in a domain with a domain element's tags. Individual amino acids are the building blocks of proteins.