Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

On the evolution of beta-galactosidase.

J M Hood, A V Fowler, I Zabin

    Proceedings of the National Academy of Sciences of the United States of America
    |January 1, 1978
    PubMed
    Summary

    Beta-galactosidase (beta-D-galactoside galactohydrolase) shows internal homology between its first three-fourths. Its carboxyl-terminal region is homologous to E. coli dihydrofolate reductase, suggesting evolutionary origins.

    Related Concept Videos

    You might also read

    Related Articles

    Articles linked to this work by shared authors, journal, and citation graph.

    Sort by
    Same author

    Stable isotopes reveal an imprint of harmful algal blooms on Lake Erie.

    Aquatic ecosystem health & management·2026
    Same author

    Anthropogenic change decouples a freshwater predator's density feedback.

    Scientific reports·2023
    Same author

    Positive fluid balance is associated with complications after elective open infrarenal abdominal aortic aneurysm repair.

    European journal of vascular and endovascular surgery : the official journal of the European Society for Vascular Surgery·2007
    Same author

    The Belfast approach to managing complex lower limb vascular injuries.

    European journal of vascular and endovascular surgery : the official journal of the European Society for Vascular Surgery·2006
    Same author

    Periods of low atmospheric pressure are associated with high abdominal aortic aneurysm rupture rates in Northern Ireland.

    The Ulster medical journal·2005
    Same author

    If I can see so far. Annual oration: Royal Victoria Hospital Belfast, October 2004.

    The Ulster medical journal·2005

    Area of Science:

    • Biochemistry
    • Molecular Biology
    • Evolutionary Biology

    Background:

    • Beta-galactosidase (beta-D-galactoside galactohydrolase, EC 3.2.1.23) is a crucial enzyme in lactose metabolism.
    • Understanding protein sequence homology aids in elucidating evolutionary relationships and functional insights.

    Purpose of the Study:

    • To investigate the internal sequence similarity within beta-galactosidase.
    • To explore potential homologies between beta-galactosidase and other known proteins.
    • To propose a model for the evolutionary origin of beta-galactosidase.

    Main Methods:

    • Comparative analysis of the amino acid sequence of beta-galactosidase.
    • Sequence alignment to identify regions of similarity and identity with other proteins, including dihydrofolate reductase and lac repressor.

    Main Results:

    • Two distinct segments within the first three-fourths of beta-galactosidase exhibit significant sequence similarity, indicating internal homology.
    • The carboxyl-terminal region of beta-galactosidase shares a high percentage of amino acid identities with dihydrofolate reductase from Escherichia coli, suggesting homology.
    • No significant sequence similarity was found between beta-galactosidase and lac repressor.

    Conclusions:

    • Beta-galactosidase likely evolved through gene duplication events, as evidenced by its internal homology.
    • The homology with dihydrofolate reductase suggests a shared evolutionary ancestry for these enzymes.
    • The distinct structural and functional roles of beta-galactosidase and lac repressor are reflected in their lack of significant sequence similarity.

    Related Experiment Videos