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

A Euglena gracilis zinc endonuclease

M Czupryn1, K H Falchuk, A Stankiewicz

  • 1Center for Biochemical and Biophysical Sciences and Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115.

Biochemistry
|February 9, 1993
PubMed
Summary

A novel zinc-containing endonuclease from Euglena gracilis degrades DNA and enhances RNA synthesis. This enzyme

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

Diagnostic test accuracy of magnetic resonance imaging and pelvic floor ultrasound for diagnosis of levator ani muscle avulsion.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology·2022
Same author

Parathyroid hormone reference ranges in healthy individuals classified by vitamin D status.

Journal of endocrinological investigation·2019
Same author

Beneficial effect of combined spironolactone and quinapril treatment on thrombosis and hemostasis in 2K1C hypertensive rats.

Journal of physiology and pharmacology : an official journal of the Polish Physiological Society·2018
Same author

Does 4D transperineal ultrasound have additional value over 2D transperineal ultrasound for diagnosing posterior pelvic floor disorders in women with obstructed defecation syndrome?

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology·2018
Same author

Stabilization of the Amorphous Ezetimibe Drug by Confining Its Dimension.

Molecular pharmaceutics·2016
Same author

Report Summary--Rio Political Declaration on Social Determinants of Health: A Snapshot of Canadian Actions 2015.

Health promotion and chronic disease prevention in Canada : research, policy and practice·2015

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Enzymology

Background:

  • Euglena gracilis is a unique eukaryotic microorganism.
  • Endonucleases play crucial roles in DNA metabolism and regulation.
  • Metal ions are essential cofactors for many enzymatic activities.

Purpose of the Study:

  • To purify and characterize a novel endonuclease from zinc-sufficient Euglena gracilis.
  • To investigate the DNA-degrading and RNA synthesis-enhancing activities of the enzyme.
  • To determine the metal ion requirements and sensitivity to chelators.

Main Methods:

  • Protein purification to homogeneity.
  • Nucleolytic activity assays using supercoiled and single-stranded DNA.
  • In vitro transcription assays with RNA polymerase II.
  • Metal ion analysis using atomic absorption spectrometry.
  • Enzyme inhibition studies with metal chelators.

Main Results:

  • A 26-kDa endonuclease was purified, exhibiting higher affinity for single-stranded DNA but degrading both single and double-stranded DNA.
  • The enzyme enhanced RNA synthesis by RNA polymerase II up to 3-fold.
  • DNA hydrolysis and transcription enhancement required magnesium or other divalent metal ions (Mn2+, Zn2+, Co2+).
  • Metal chelators (OP, HQSA) completely inhibited both DNA digestion and transcription enhancement.
  • The enzyme isolated from zinc-sufficient cells contained zinc, while from zinc-deficient cells, it contained copper instead of zinc.

Conclusions:

  • The purified endonuclease possesses unique DNA degradation and RNA synthesis-stimulating properties.
  • The enzyme's activity is dependent on divalent metal ions, with zinc being a key component in zinc-sufficient conditions.
  • The metal-binding site is crucial for both nucleolytic and transcription-enhancing functions.
  • The presence of copper in zinc-deficient conditions suggests potential metal-dependent regulation or alternative functions.

Related Experiment Videos