Helicase

Helicase is a type of enzyme that is essential for all organisms. Their main function is to unpackage an organism's genes. They are known as helicases due to their ability to unwind the helical DNA structure. They are essential for most processes where nucleic acids are involved, such as DNA replication, DNA repair, transcription, and translation.

Function

Helicases move along the nucleic acid phosphodiester backbone, separating two annealed nucleic acid strands (i.e., DNA, RNA, or RNA-DNA hybrid) using energy from ATP hydrolysis. There are many helicases resulting from the great variety of processes in which strand separation must be catalyzed.

Structure

Most of the helicases are composed of two or three domains. A domain is a part of the protein that can exist independently of the rest of the protein chain. Each domain forms part of the active site of the enzyme. The active site is the region of the enzyme where substrate molecules bind and undergo a chemical reaction.

Role in Disease

Mutations in the genes encoding helicases can lead to genetic diseases such as Werner's syndrome, which is characterized by premature aging, and Bloom syndrome, which increases the risk of cancer.

See Also

• DNA replication
• DNA repair
• Transcription
• Translation

Helicase

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  Helicase
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  RecQ helicase
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  Human DEAD-box RNA helicase
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  DEAD box Accessory Domains