IUBMB Enzyme Nomenclature


Accepted name: RNA helicase

Reaction: ATP + H2O = ADP + phosphate

Other name(s): CSFV NS3 helicase; DBP2; DbpA; DDX17; DDX25; DDX3; DDX3X; DDX3Y; DDX4; DDX5; DEAD-box protein DED1; DEAD-box RNA helicase; DEAH-box protein 2; DEAH-box RNA helicase; DED1; Dex(H/D) RNA helicase; EhDEAD1; EhDEAD1 RNA helicase; eIF4A helicase; KOKV helicase; Mtr4p; nonstructural protein 3 helicase; NPH-II; RHA; RNA helicase A; RNA helicase DDX3; RNA helicase Hera; RNA-dependent ATPase; TGBp1 NTPase/helicase domain; VRH1; GRTH/DDX25

Systematic name: ATP phosphohydrolase (RNA helix unwinding)

Comments: RNA helicases utilize the energy from ATP hydrolysis to unwind RNA. Some of them unwind RNA with a 3' to 5' polarity [3], other show 5' to 3' polarity [8]. Some helicases unwind DNA as well as RNA [7,8]. May be identical with EC (DNA helicase).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Cordin, O., Tanner, N.K., Doere, M., Linder, P. and Banroques, J. The newly discovered Q motif of DEAD-box RNA helicases regulates RNA-binding and helicase activity. EMBO J. 23 (2004) 2478-2487. [PMID: 15201868]

2. Rodamilans, B. and Montoya, G. Expression, purification, crystallization and preliminary X-ray diffraction analysis of the DDX3 RNA helicase domain. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 63 (2007) 283-286. [PMID: 17401195]

3. Lee, C.G. and Hurwitz, J. A new RNA helicase isolated from HeLa cells that catalytically translocates in the 3' to 5' direction. J. Biol. Chem. 267 (1992) 4398-4407. [PMID: 1537828]

4. Li, S.C., Chung, M.C. and Chen, C.S. Cloning and characterization of a DEAD box RNA helicase from the viable seedlings of aged mung bean. Plant Mol. Biol. 47 (2001) 761-770. [PMID: 11785937]

5. Wu, J., Bera, A.K., Kuhn, R.J. and Smith, J.L. Structure of the Flavivirus helicase: implications for catalytic activity, protein interactions, and proteolytic processing. J. Virol. 79 (2005) 10268-10277. [PMID: 16051820]

6. Gross, C.H. and Shuman, S. The nucleoside triphosphatase and helicase activities of vaccinia virus NPH-II are essential for virus replication. J. Virol. 72 (1998) 4729-4736. [PMID: 9573237]

7. Frick, D.N. The hepatitis C virus NS3 protein: a model RNA helicase and potential drug target. Curr. Issues Mol. Biol. 9 (2007) 1-20. [PMID: 17263143]

[EC created 2009]

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