Helicases are classes of enzymes that help in unwinding the DNA during replication and also help in DNA repair. It uses energy in the form of nucleoside triphosphates (NTP) to unwind the double-stranded DNA (dsDNA).
Structurally, the helicases show amino acid homology and have specific sequence motifs (nucleotide sequence related to a biological function) in their primary structures. Based on the sequence motifs, the helicases are divided into six superfamilies. Superfamily 1 and 2 do not form any ring structures, while superfamilies 3 to 6 form a ring structure of helicases.
Now let us find out the differences between Superfamily 1 and 2.
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Superfamily 1 (SF1) is a family of helicases that functions to unwind DNA and RNA during replication and recombination. |
Superfamily 2 (SF2) is another family of helicases that functions in DNA and RNA metabolism apart from unwinding. |
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They have both conserved and non-conserved motifs in their primary structure. |
They have a characteristic 9 conserved motif in their primary structure. |
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Rep, UvrD, PcrA |
RecQ, Snf2, RecA |
This sums up the differences between SF1 and SF2 of helicases.
Visit BYJU’S Biology to learn more about DNA and RNA.
Also Read:
- How Many Stages Are There in DNA Replication?
- What is the importance of DNA replication?
- DNA Replication Process with Diagrams
Frequently Asked Questions
What is hexameric helicase?
What are the two functions of helicase?
The two main functions of helicases are the unwinding of DNA and RNA metabolism.
Where is helicase found?
Helicases are found in all living organisms and viruses.
Does transcription need helicase?
Yes, helicases are required for transcription initiation.
Who discovered DNA helicase?
DNA helicases were discovered in 1976 by Hoffmann-Berling and his colleagues at the University of Heidelberg and by Mackay and Linn at the University of California, Berkeley.
How does helicase separate DNA?
Helicase enzyme breaks down the hydrogen bonds between the two strands of DNA to separate them.
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