Related Experiment Video

Updated: Aug 27, 2026

Use of Single Chain MHC Technology to Investigate Co-agonism in Human CD8+ T Cell Activation
12:09

Use of Single Chain MHC Technology to Investigate Co-agonism in Human CD8+ T Cell Activation

Published on: February 28, 2019

Domain structures and molecular evolution of class I and class II major histocompatibility gene complex (MHC)

K Ohnishi

    Origins of Life
    |January 1, 1984
    PubMed

    Domain structures of class I and class II MHC products were analyzed from a viewpoint of amino acid and nucleotide sequence homologies. Alignment statistics revealed that class I (transplantation) antigen H chains consist of four mutually homologous domains, and that class II (HLA-DR) antigen beta and alpha chains are both composed of three mutually homologous ones. The N-terminal three and two domains of class I and class II (both beta and alpha) gene products, respectively, all of which being approximately 90 residues long, were concluded to be homologous to beta2-microglobulin (beta2M). The membrane-embedded C-terminal shorter domains of these MHC products were also found to be homologous to one another and to the third domain of class I H chains. Class I H chains were found to be more closely related to class II alpha chains than to class II beta chains. Based on these findings, an exon duplication history from a common ancestral gene encoding a beta2M-like primodial protein of one-domain-length up to the contemporary MHC products was proposed.

    More Related Videos

    Stability and Structure of Bat Major Histocompatibility Complex Class I with Heterologous β2-Microglobulin11:17

    Stability and Structure of Bat Major Histocompatibility Complex Class I with Heterologous β2-Microglobulin

    Published on: March 10, 2021

    Immunopeptidomics: Isolation of Mouse and Human MHC Class I- and II-Associated Peptides for Mass Spectrometry Analysis09:32

    Immunopeptidomics: Isolation of Mouse and Human MHC Class I- and II-Associated Peptides for Mass Spectrometry Analysis

    Published on: October 15, 2021

    Related Concept Videos

    Protein Families02:47

    Protein Families

    Protein families are groups of homologous proteins; that is, they have similarities in amino acid sequences and three-dimensional structures. Protein families usually occur because of gene duplication, where an additional copy of a gene is inserted into the genome of an organism.   Mutations that change the amino acids but still allow the protein to be properly synthesized, will lead to new protein family members.   If these new proteins contain similar amino acids in key locations, protein...
    Evolutionary Relationships through Genome Comparisons02:54

    Evolutionary Relationships through Genome Comparisons

    Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse...
    Antigens Involved in Adaptive Immunity01:26

    Antigens Involved in Adaptive Immunity

    An antigen is any substance the immune system identifies as foreign and potentially harmful to the body, prompting an immune response. Antigens have two functional properties: immunogenicity and reactivity. Immunogenicity is the ability of an antigen to stimulate a specific immune response. At the same time, reactivity describes the antigen's ability to react with the cells and antibodies produced in response to it.
    Complete Antigens
    Complete antigens possess both immunogenicity and reactivity.
    Antigen Processing Pathways01:31

    Antigen Processing Pathways

    MHC molecules are key players in the immune response, enabling T cells to recognize and respond to specific antigens. They are present on the surface of all nucleated cells in the body and are instrumental in presenting antigens to T cells and activating them. T cells recognize the MHC-antigen complex and initiate an immune response. MHC class I and MHC class II are two main types of MHC molecules, each associated with a distinct antigen processing pathway.
    MHC Class I: Presenting Endogenous...
    Modern Molecular Taxonomy01:29

    Modern Molecular Taxonomy

    Advancements in molecular biology have revolutionized the identification and characterization of bacteria, with multiple methods leveraging DNA sequencing for enhanced precision. As sequencing technologies improve and costs decline, these approaches are increasingly used in clinical, environmental, and evolutionary studies.Multilocus Sequence Typing (MLST) examines several housekeeping genes, essential chromosomal genes encoding cellular functions, to distinguish strains. Approximately...
    Microbial Phylogeny01:28

    Microbial Phylogeny

    Understanding the evolutionary relationships among microorganisms is fundamental to microbial ecology and taxonomy. Phylogenetic trees are essential tools for inferring these relationships, relying primarily on comparative analyses of molecular sequences such as DNA, RNA, or proteins. In microbial studies, these trees typically depict the evolutionary paths of diverse bacterial and archaeal species by mapping genetic differences accumulated over time.Phylogenetic trees are composed of tips,...