The Sequence Feature Variant Type (SFVT) refers to the defined mutation of a given sequence feature in a protein

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...

. Consider a protein, its amino acid sequence determines the its structure and function. Some regions of the sequence are primarily related to the protein folding

Protein folding

Protein folding is the process by which a protein structure assumes its functional shape or conformation. It is the physical process by which a polypeptide folds into its characteristic and functional three-dimensional structure from random coil....

, thus the structure, while other regions are related to the protein function, such as a transmembrane protein

Transmembrane protein

A transmembrane protein is a protein that goes from one side of a membrane through to the other side of the membrane. Many TPs function as gateways or "loading docks" to deny or permit the transport of specific substances across the biological membrane, to get into the cell, or out of the cell as...

, or as an enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

. Across many related species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

, regions in a corresponding protein would remain conserved from species to species, while the exact amino acid at each location might, and often do, change. To clearly illustrate both the conserved nature of the functional regions and the precise change in the actual amino acid, the Sequence Feature Variant Type is defined.

Sequence Feature

A sequence feature is basically a collection of amino acids within a protein, where the collection may be a continuous range or some discreet residues. Most sequence features are from experimental results, but there are some that are from computational analysis.

Sequence Feature Variant Type

For each sequence feature, the variations exist between many proteins from different related species. The variant types define the exact amino acid at each location for a feature. The larger the mutation at each location for a feature, the larger its number of variant types. For a given protein, once its amino acid sequence is determined, its sequence feature variant type is determined.

Application

SFVTs can be used to study the protein functions across many related species. Such studies have been carried out on several human pathogens.

SFVTs are also available on Influenza Research Database

Influenza Research Database

The Influenza Research Database is an integrative and comprehensive publicly-available database and analysis resource to search, analyze, visualize, save and share data for influenza virus research...

 for flu proteins and on Virus Pathogen Database and Analysis Resource

Virus Pathogen Database and Analysis Resource

The Virus Pathogen Database and Analysis Resource is an integrative and comprehensive publicly available database and analysis resource to search, analyze, visualize, save and share data for viral pathogens in the U.S...

for Dengue virus.