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ENZYME

ENZYME entry: EC 5.6.2.6

PURL: https://purl.expasy.org/enzyme/EC/5.6.2.6
Accepted Name
RNA 3'-5' helicase
Reaction catalysed
n ATP + n H2O + wound RNA = n ADP + n phosphate + unwound RNA
Comment(s)
  • RNA helicases, which participate in nearly all aspects of RNA metabolism, utilize the energy from ATP hydrolysis to unwind RNA.
  • The engine core of helicases is usually made of a pair of RecA-like domains that form an NTP binding cleft at their interface.
  • Changes in the chemical state of the NTP binding cleft (binding of the NTP or its hydrolysis products) alter the relative positions of the RecA-like domains and nucleic acid-binding domains, creating structural motions that disrupt the pairing of the nucleic acid, causing separation and unwinding.
  • Most RNA helicases utilize a mechanism known as canonical duplex unwinding, in which the helicase binds to a single stranded region adjacent to the duplex and then translocates along the bound strand with defined directionality, displacing the complementary strand.
  • Most of these helicases proceed 3' to 5' (type A polarity), but some proceed 5' to 3' (type B polarity - cf. EC 5.6.2.5), and some are able to catalyze unwinding in either direction.
  • Most canonically operating helicases require substrates with single stranded regions in a defined orientation (polarity) with respect to the duplex.
  • A different class of RNA helicases, EC 5.6.2.7, use a different mechanism and unwind short stretches of RNA with no translocation.
Cross-references
BRENDA5.6.2.6
EC2PDB5.6.2.6
ExplorEnz5.6.2.6
KEGG Ligand Database for Enzyme Nomenclature5.6.2.6
IUBMB Enzyme Nomenclature5.6.2.6
MEDLINEFind literature relating to 5.6.2.6
MetaCyc5.6.2.6
Rhea expert-curated reactions5.6.2.6

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All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 5.6.2.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 5.6.-.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 5.-.-.-