This document provides information about restriction enzymes including their definition, history, origin, types, and applications. Restriction enzymes are enzymes that cleave DNA at specific restriction sites. They were first discovered in the 1960s by scientists studying E. coli bacteria. There are four main types of restriction enzymes that are classified based on differences in their structure and cleavage/recognition sites. Restriction enzymes have various applications in gene cloning, protein expression experiments, and biotechnology.

2. Presentation By
RANI SUMMEYA SEME
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3.  Definition
 History
 Location
 Origin
 Nomenclature
 Function
 Recognition site
 Types
 Artificial R E
 Application

4. Restriction enzymes:-
Enzyme
Cleaves DNA
At restriction site
Molecular scissor

5.  1960 Stewart Linn & Werner Arber---- E.coli
 Hamilton Smith---- HindII ---specificity in cutting
W. Arber H. O. Smith

6.  Bacteria
 Archea
Provide a defense mechanism against invading virus
Origin
Restriction Enzymes originate from
 Common ancestor via
 Horizontal gene transfer
Selfish Genetic Element--- no contribution to
reproductive process

7. Derivation of the EcoRI name
Abbreviation Meaning Description
E Escherichia Genus
co coli specific epithet
R RY13 Strain
I First identified
order of identification
in the bacterium

9.  Sequence of nucleotide
 Produced double stranded cut
 Palindromic Sequence
Types of palindromic sequence
1. Mirror Like Palindrome
GTAATG
2. Inverted Repeat Palindrome (imp)
GTATAC
CATATG

10. Blunt end
Sticky end (useful)

11.  Neoschizomers
 Isoschizomers

12.  Four types
 Based on
 Difference of structure
 Location of cut
 Cleavage & recognition site
Type 1 RE:-
• Cleave away from recognition site
• Require--- ATP & S-adenosyl-l-methionine
• Multifunctional

13. Type 2 RE:-
• Cleave within or short distance from recognition site
• Most require Magnesium
• Monofunctional
• Independent of methylase
Type 3 RE:-
• Cleave at short distance from recognition site
• Require
• ATP( but don’t hydrolyze it)
• S-adenosyl-l-methionine (stimulate reaction, not necessary)
• Exist as part of complex

14. Type 4 RE:-
• Target modified DNA eg
• Metylated
• Hydroxymethylated
Artificial restriction enzymes
 Can be generated by fusing
• DNA Domain
• Nuclease Domain
 Target large DNA site
 Eg Zinc Finger Nucleases

15. Restriction Enzymes are used in
• Gene Cloning
• Protein Expression Experiments
• Biotechnology (to study RFLPS)