Restriction endonucleases are enzymes produced by bacteria that cut DNA molecules at specific recognition sequences. They play an important role in bacteria's defense against viruses by degrading viral DNA. There are four main types of restriction enzymes based on their subunit structure and cofactors required. Type II enzymes are the most commonly used as they recognize palindromic sequences 4-8 base pairs in length and cleave DNA at the recognition site, requiring only magnesium as a cofactor. Restriction fragments can have either blunt or sticky ends, which allows for joining of DNA fragments. Isoschizomers recognize the same sequence but cut in the same location, while neoschizomers recognize the same sequence but cut in different locations.
Also referred to as Restriction Endonucleases
Molecular scissors that cut double stranded DNA molecules at specific points.
Found naturally in a wide variety of prokaryotes
An important tool for manipulating DNA.
Enters and recognizes a certain sequence on a double helix strand of DNA, usually 4-6 base-pairs long, and cuts it.
Precise by cutting both strands in same location though strands move in reverse directions; REs are able to depict the precise spot to cut
Also referred to as Restriction Endonucleases
Molecular scissors that cut double stranded DNA molecules at specific points.
Found naturally in a wide variety of prokaryotes
An important tool for manipulating DNA.
Enters and recognizes a certain sequence on a double helix strand of DNA, usually 4-6 base-pairs long, and cuts it.
Precise by cutting both strands in same location though strands move in reverse directions; REs are able to depict the precise spot to cut
in gene cloning technique the cutting of DNA is essential. With the help of restriction endonuclease, it has been done. It also describes the restriction digest of a DNA molecule.
Restriction Endonuclease: The Molecular Scissor of DNA - By RIKI NATHRIKI NATH
restriction enducleases are called the molecular scissors of DNA. types of restriction enzymes, their structures, subunits, most importantly the use of Type II restriction endonuclease in recombinant technology, mechanism of enzyme action and their applications.
in gene cloning technique the cutting of DNA is essential. With the help of restriction endonuclease, it has been done. It also describes the restriction digest of a DNA molecule.
Restriction Endonuclease: The Molecular Scissor of DNA - By RIKI NATHRIKI NATH
restriction enducleases are called the molecular scissors of DNA. types of restriction enzymes, their structures, subunits, most importantly the use of Type II restriction endonuclease in recombinant technology, mechanism of enzyme action and their applications.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Normal Labour/ Stages of Labour/ Mechanism of LabourWasim Ak
Normal labor is also termed spontaneous labor, defined as the natural physiological process through which the fetus, placenta, and membranes are expelled from the uterus through the birth canal at term (37 to 42 weeks
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
3. Introduction
• Restriction Endonucleases are enzymes that produce
internal cuts, called cleavage, In the DNA molecule.
• Restriction Endonuclease (Restriction Enzyme) is a bacterial
enzyme that cuts dsDNA into fragments after recognizing
specific nucleotide sequence known as recognition or
restriction site.
• Restriction Enzymes are believed to be evolved by bacteria to
resist viral attack.
• Restriction Enzymes are also known as molecular scissor.
4. • Restriction Enzymes scan the DNA sequence
• Find a very specific set of nucleotides
• Make a specific cut
5. Palindromes in DNA sequences
Genetic palindromes
are similar to verbal
palindromes. A
palindromic sequence
in DNA is one in which
the 5’ to 3’ base pair
sequence is identical
on both strands.
5’
5’
3’
3’
6. The discovery and function of Restriction Endonucleases
The initial observation that led to the eventual discovery of
restriction endonucleases was made during the early 1950s,
when some strains of bacteria were shown to be immune to
bacteriophage infection, a phenomenon referred to as host-
controlled restriction.
The mechanism of restriction is not very complicated, even
though it took over 20 years to be fully understood. Restriction
occurs because the bacterium produces an enzyme that
degrades the phage DNA before it has time to replicate and
direct the synthesis of new phage particles
7.
8.
9.
10. Type I
• Capable of both restriction and modification
activities
• The co factors S-Adenosyl Methionine(AdoMet),
ATP, and mg+are required for their full activity
• Contain:
two R (restriction) subunits
two M (methylation) subunits
one S (specifity) subunits
• Cleave DNA at random length from recognition
sites
11. Type II
• These are the most commonly available and used
restriction enzymes
• They are composed of only one subunit.
• Their recognition sites are usually undivided and
palindromic and 4-8 nucleotides in length,
• They recognize and cleave DNA at the same site.
• They do not use ATP for their activity
• They usually require only Mg2+ as a cofactor.
12. Type III
• Type III restriction enzymes ) recognize two separate
non-palindromic sequences that are inversely
oriented.
• They cut DNA about 20-30 base pairs after the
recognition site.
• These enzymes contain more than one subunit.
• And require AdoMet and ATP cofactors for their roles
in DNA methylation and restriction
13. Types of Restriction Enzymes
Cleavage
site
Location of
methylase
Requirements for
activity Examples
Type
I
Random,
Around 100-
1000bp away
from recogni-
tion site
Endonuclease
and methylase
located on a
single protein
molecule
co factors S-Adenosyl
Methionine (AdoMet)
, ATP and mg+
EcoK I
EcoA I
CfrA I
Type
II
Specific,
Within the
recognition
site
Endonuclease
and methylase
are separate
entities
Mg2+ EcoR I
BamH I
Hind III
Type
III
Random
20-30 bp
away from
recognition
site
Endonuclease
and methylase
located on a
single protein
molecule
AdoMet and ATP
cofactors
EcoP I
Hinf III
EcoP15 I
14. Restriction fragments can be blunt ended
or sticky ended
5’ G A A T T C 3’ 5’ G A T A T C 3’
3’ C T T A A G 5’ 3’ C T A T A G 5’
Sticky Ends Blunt Ends
Sticky ends or blunt ends can be used to join DNA
fragments.
Sticky ends are more cohesive compared to blunt ends.
17. • Isoschizomers are restriction enzymes that have the same recognition
sequence and the same specificity. For instance, AgeI and BshT1 recognize and
cleave 5′-A↓CCGGT-3′ in the same pattern. Nevertheless, a set of
isoschizomers may differ in site preferences, reaction conditions, methylation
sensitivity, and star activity. (Learn more: Restriction enzyme isoschizomers
and key considerations).
• Neoschizomers recognize the same nucleotide sequence but cleave DNA at
different positions. Examples of neoschizomers are SmaI (5′-CCC↓GGG-3′) and
XmaI (5′-C↓CCGGG-3′), which both recognize 5′-CCCGGG-3′ but cleave them
differently and thus generate different types of ends (in this case, blunt ends
for SmaI and 5′ protruding ends for XmaI).
Isoschizomers and Neochischizomers