The key difference between EcoRI and HindIII restriction enzymes is that EcoRI is a type II restriction enzyme that is isolated from E. coli, while HindIII is a type II restriction enzyme that is isolated from Haemophilus influenza.
Restriction enzyme or restriction endonuclease is an enzyme that cleaves DNA into fragments at specific recognition sites (restriction sites) within the DNA molecule. These restriction enzymes are found in bacteria and archaea. They provide a defense mechanism against invading viruses. Restriction enzymes are generally classified into five different types: type I, type II, type III, IV, and type V. EcoRI and HindIII are two restriction enzymes that belong to the group of type II restriction enzymes.
CONTENTS
1. Overview and Key Difference
2. What are EcoRI Restriction Enzymes
3. What are HindIII Restriction Enzymes
4. Similarities Between – EcoRI and HindIII Restriction Enzymes
5. EcoRI vs HindIII Restriction Enzymes in Tabular Form
6. Summary – EcoRI vs HindIII Restriction Enzymes
What are EcoRI Restriction Enzymes?
EcoRI is a type II restriction enzyme that is isolated from E.coli species. It is a restriction enzyme that cleaves DNA double helices into fragments at specific sites. EcoRI is also a part of the restriction-modification system. EcoRI was the first enzyme that was originally isolated from the RY13 strain of the E. coli species. It is used as a restriction enzyme in molecular biology. EcoRI creates 4 nucleotide sticky ends with 5’ end overhangs of AATT. EcoRI cuts the DNA at the specific recognition sequence G↓AATTC. It has the palindromic complementary sequence of CTTAA↓G. Moreover, this restriction enzyme belongs to the type II P (palindromic specificity) subclass. In its primary structure, EcoRI contains the PD..D/EXK motif within its active site, like many other restriction enzymes.
Figure 01: EcoRI
EcoRI restriction enzyme is a homodimer of a 31 kDa. It contains one globular domain of the α/β architecture. Each subunit contains a loop that sticks out from the globular domain and wraps around the DNA when bound. This enzyme can be cocrystallized with the sequence it normally cuts. Furthermore, the EcoRI restriction enzyme is used in a wide variety of molecular genetic techniques, including cloning, DNA screening, and deletion sections of DNA in-vitro conditions.
What are HindIII Restriction Enzymes?
HindIII is a type II restriction enzyme that is isolated from Haemophilus influenza species. It cleaves the DNA palindromic sequence AACCTT in the presence of the cofactor Mg2+ through hydrolysis. The cleavage of this particular sequence between the AA’S (5’A↓ACCTT3’ and 3’TTCGA↓A5’) results in 5’ overhangs on the DNA molecule called sticky ends. This enzyme is found in prokaryotic organisms like bacteria. Bacteria use this enzyme as a defense mechanism against viruses such as bacteriophages.
Figure 02: HindIII
Structurally, HindIII is a homodimer. It contains a common structural core comprising four β sheets and a single α helices, like other types of II restriction enzymes. The molecular mass of this enzyme is 34.9 kDa. Furthermore, HindIII is very useful in modern molecular biological science experiments such as DNA sequencing and mapping.
What are the Similarities Between EcoRI and HindIII Restriction Enzymes?
- EcoRI and HindIII are two restriction enzymes belonging to the type II restriction enzyme group.
- EcoRI and HindIII were found in the early 1970s.
- EcoRI and HindIII both contain the PD..D/EXK amino acid sequence motif.
- Both restriction enzymes perform very specific cleaving of the DNA.
- These restriction enzymes need Mg2+ as a cofactor for their specific activity.
- They produce sticky ends after cutting DNA.
- They are very useful components in modern molecular biological research.
What is the Difference Between EcoRI and HindIII Restriction Enzymes?
EcoRI is a type II restriction enzyme that is isolated from E.coli species, while HindIII is a type II restriction enzyme that is isolated from Haemophilus influenza species. Thus, this is the key difference between EcoRI and HindIII. Furthermore, EcoRI cuts the DNA at the specific recognition sequence G↓AATTC, while HindIII cuts the DNA at the specific recognition sequence A↓ACCTT.
The below infographic presents the differences between EcoRI and HindIII in tabular form for side by side comparison.
Summary – EcoRI vs HindIII Restriction Enzymes
EcoRI and HindIII are two restriction enzymes that belong to the type II p subclass. They perform very specific cleaving of the DNA. EcoRI is a type II restriction enzyme that is isolated from E.coli species, while HindIII is a type II restriction enzyme that is isolated from Haemophilus influenza species. So, this summarizes the difference between EcoRI and HindIII.
Reference:
1. “ECORI.” EcoRI – An Overview | ScienceDirect Topics.
2. “HINDIII-HF®.” New England Biolabs: Reagents for the Life Sciences Industry.
Image Courtesy:
1. “Ecor1 2ckq” By A2-33 – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “HindIII Restriction site and sticky ends vector” By Helixitta – Own work (CC BY-SA 4.0) via Commons Wikimedia