What is the Difference Between Multigene Families and Superfamilies

The key difference between multigene families and superfamilies is that multigene families are groups of genes with sequence homology, while superfamilies are groups of proteins or genes of common origin.

Multigene families and superfamilies are groups of genes and proteins families that have structurally similar genes and proteins. A gene family is a set of similar genes formed by the duplication of a single original gene. Generally, they have a similar biochemical function as well. A protein family is a group of evolutionarily related proteins. Typically, proteins in a family are descended from a common ancestor. Both gene and protein families form a hierarchy of information storage about genomes and play a huge role in the evolution and diversity of organisms.

CONTENTS

1. Overview and Key Difference
2. What are Multigene Families 
3. What are Superfamilies
4. Similarities – Multigene Families and Superfamilies
5. Multigene Families vs Superfamilies in Tabular Form
6. Summary – Multigene Families vs Superfamilies

What are Multigene Families?

Multigene families are groups of genes with sequence homology and related overlapping functions. Multigene families normally consist of members with similar sequences and functions. Gene duplication and divergence are the major phenomena behind the origin of such multigene families.

Individual genes in multigene families can be arranged close together on the same chromosome, or these individual genes can be dispersed throughout the genome on different chromosomes. These genes in the multigene families often share regulatory control elements. This is due to their sequence similarity and overlapping functions. In some cases, multigene families have members that share nearly identical sequences. Therefore, such multigene families allow massive amounts of gene products to be expressed in a short period of time when it is needed. However, other multigene families allow similar but specific gene products to be expressed in different cell types or different stages of the development of an organism. Some of the well-known multigene families are those that code for actins, immunoglobulins, tubulins, hemoglobins, interferons, histones, etc.

What are Superfamilies?

Superfamilies are groups of proteins or genes of common origin with non-overlapping functions. Protein superfamilies are the largest grouping of proteins based on their common ancestries. The common ancestry is inferred from structural alignments and mechanistic similarities. Protein superfamilies normally contain several protein families, which show sequence similarity within each family. Some of the well-known examples for protein superfamilies are protease, glycosyl hydrolases, alkaline phosphatase, globin, PA clan, Ras, serpin, TIM barrel, etc. Protein superfamilies are evolutionary very significant. This is because they represent the current limits of scientists’ ability to identify common ancestry.

Gene superfamilies are much larger than multigene families. Gene superfamilies usually contain up to hundreds of genes, including multiple multigene families. The genes in superfamilies are diverse in sequence and function and display various levels of expression. These genes also have separate regulation controls. The globin superfamily of genes is the most common example of gene superfamilies.

What are the Similarities Between Multigene Families and Superfamilies?

• Multigene families and superfamilies are groups of genes and proteins families that have structurally similar genes and proteins.
• Immunoglobulins and globins are included in both families.
• Both families are evolutionary important.
• Sequence alignments can be used to form both families.

What is the Difference Between Multigene Families and Superfamilies?

Multigene families are groups of genes with sequence homology, while superfamilies are groups of proteins or genes of common origin. So, this is the key difference between multigene families and superfamilies. Furthermore, multigene families are groups of genes with related overlapping functions, while superfamilies are groups of proteins or genes with non-overlapping functions.

The below infographic lists the differences between multigene families and superfamilies in tabular form for side by side comparison.

Summary – Multigene Families vs Superfamilies

Multigene families and superfamilies are groups of genes and proteins families that have structurally similar genes and proteins. They are evolutionary very important. Multigene families are groups of genes with sequence homology, while superfamilies are groups of proteins or genes of common origin. Thus, this is the key difference between multigene families and superfamilies.

Reference:

1. “Multigene Family.” An Overview | ScienceDirect Topics.
2. “Protein Superfamily.” An Overview | ScienceDirect Topics.

Image Courtesy:

1. “Evolution of the hGH-hPL multigene family” By BQUB19-LFerres – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Structural homology of the PA clan” By Thomas Shafee – Own work (CC BY 4.0) via Commons Wikimedia