This document presents information about restriction endonucleases. It begins with an introduction and history, then discusses the nomenclature, recognition sequences, and classification of restriction endonucleases. It describes the four main types of restriction endonucleases, their subunit composition, cofactors used, characteristics, and mechanisms of action. The document concludes with references cited.

1. RESTRICTION
ENDONUCLEASE
Presented by:
Asha Raj
Inchara R
VII Semester
Molecular Biology
Yuvaraja College
(Autonomous)
Mysuru

2. CONTENTS
• INTRODUCTION
• HISTORY
• NOMENCLATURE
• RECOGNITION SEQUENCES AND CLEAVAGE
• CLASSIFICATION
• MECHANISM
• CONCLUSION
• REFERENCES
• ACKNOWLEDGEMENT

3. INTRODUCTION
Fig 01: Classification of enzymes used in Genetic Engineering

4. Fig 02: Breakage of Phosphodiester linkage by REase activity

5. HISTORY
Fig 03: Joint Nobel Prize in Physiology and Medicine has been shared
by Werner Arber, Daniel Nathan, and Hamilton O Smith in 1978.

6. NOMENCLATURE
Fig 04: Examples for REase

7. RECOGNITION SEQUENCES
• Recognition sequence is the site where the DNA is cut by a restriction
endonuclease.
• The recognition site of most REases is palindromic or partially
palindromic.
• Palindrome is a word, phrase, or sentence that is spelled identically when
read either forward or backwards.
AND MADAM DNA

8. CLEAVAGE
Table 1: A selected list of enzymes/ recognition sequences, and their products
formed with Sources

9. Type I
Hetero-oligomer of R, M
and S subunits
S-adenosyl-L-methionine
(AdoMet), ATP & Mg 2+
Multi subunit complex
(2R, 2M & 1S), 1000bp
away.
Cleavage at random site
away from the
recognition site
Type II
Homo di or tetramer
of R subunit
Mg 2+
Many subtypes
(Type IIG, IIP & IIS)
Cleave DNA
specifically near to
the recognition site
Features
Subunit
Composition
Cofactors
Characteristics
Action
Type III
Heterotrimers (M2R1) or
Heterotetramers (M2R2)
AdoMet, ATP & Mg 2+
Restriction &
modification enzymes cut
at different locations
within 25bp of
recognition site
Cleave outside its
recognition sequence and
require 2 restriction sites in
opposite orientation in
same DNA.
Type IV
Single subunit with
R and M activity
Mg 2+, activity is
stimulated by
AdoMet
Cleaves exactly at
recognition site.
Normally cut
methylated DNA
Table 2: Types of restriction enzymes with characteristics features
CLASSIFICATION

10. MECHANISM
Mg2+
Fig 05: Direct hydrolysis of phosphorous atom

11. Fig 06: Bacteria fights invading viruses by making REase

12. CONCLUSION

13. REFERENCES
• Craig Heller, David Hillis, May Berenbaum & David Sadava. 2011. LIFE: The
Science of Biology, 9th Edition, Sinauer Associates, Inc., Sunderland, U.S.A,
1392pp.
• Brown T. A. 2010. Gene Cloning & DNA Analysis: An Introduction, 6th Edition,
John Wiley & Sons, Ltd., Publication, West Sussex, UK, 338pp.
• James D. Watson, Alexander Gann, Tania A. Baker, Michael Levine, Stephen P.
Bell & Richard Losick with Stephen C. Harrison. 2014. Molecular Biology of the
gene, 7th edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor,
New York, USA, 911pp.
• https://international.neb.com/products/restriction-endonucleases/restriction-
endonucleases/types-of-restriction-endonucleases
• http://epgp.inflibnet.ac.in/Home/ViewSubject?catid=3

14. ACKNOWLEDGEMENT