Verification of Mature Protein Starts


The processed forms of proteins inside of cells is the mature proteome. Verification of the mature proteome involves the experimental determination of the N-terminal residues of the mature protein. The Verified Set is a collection of proteins that have had their matured N-terminal residues sequenced using Edman degradation, as extracted from the biomedical literature. The Verified Set subTopic geneset contains all the proteins in the Verified Set. A table of the Verified Set can also be downloaded from the Download Utilities page and from the Verified Set pop-up window on the GenePages for genes that have had their mature protein starts verified. C-terminal residue sequencing is rarely done but is possible.


The mature proteome is the set of protein sequences inside of cells. It is processed from the translated proteome. This processing is of several types. Many proteins of the cells have their N-terminal formyl Methionine (fMet) residue removed by methionine aminopeptidase (Map). Type I (secreted) and Type II (lipoproteins) proteins have N-terminal signal peptides that are removed by signal peptidase I (LepB) and signal peptidase II (LspA), respectively, during the process for translocation across the inner membrane. A small number of proteins are processed from protein precursors by other proteases.