Reaction: n ATP + n H2O + wound RNA = n ADP + n phosphate + unwound RNA
Other name(s): corona virus helicase nsP13; MOV10; Moloney leukemia virus 10; UPF1; sen1+
Systematic name: RNA 5'-3' helicase (ATP-hydrolysing)
Comments: 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 - cf. EC 5.6.2.6, RNA 3'-5' helicase), but some proceed 5' to 3' (type B polarity), and some are able to catalyse unwinding in either direction [1,4]. 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, DEAD-box RNA helicase, use a different mechanism and unwind short stretches of RNA with no translocation.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Rozen, F., Edery, I., Meerovitch, K., Dever, T.E., Merrick, W.C. and Sonenberg, N. Bidirectional RNA helicase activity of eucaryotic translation initiation factors 4A and 4F. Mol. Cell Biol. 10 (1990) 1134-1144. [PMID: 2304461]
2. Kim, H.D., Choe, J. and Seo, Y.S. The sen1(+) gene of Schizosaccharomyces pombe, a homologue of budding yeast SEN1, encodes an RNA and DNA helicase. Biochemistry 38 (1999) 14697-14710. [PMID: 10545196]
3. Bhattacharya, A., Czaplinski, K., Trifillis, P., He, F., Jacobson, A. and Peltz, S.W. Characterization of the biochemical properties of the human Upf1 gene product that is involved in nonsense-mediated mRNA decay. RNA 6 (2000) 1226-1235. [PMID: 10999600]
4. Lee, C.G. RH70, a bidirectional RNA helicase, co-purifies with U1snRNP. J. Biol. Chem. 277 (2002) 39679-39683. [PMID: 12193588]
5. Gregersen, L.H., Schueler, M., Munschauer, M., Mastrobuoni, G., Chen, W., Kempa, S., Dieterich, C. and Landthaler, M. MOV10 Is a 5' to 3' RNA helicase contributing to UPF1 mRNA target degradation by translocation along 3' UTRs. Mol. Cell 54 (2014) 573-585. [PMID: 24726324]
6. Jang, K.J., Jeong, S., Kang, D.Y., Sp, N., Yang, Y.M. and Kim, D.E. A high ATP concentration enhances the cooperative translocation of the SARS coronavirus helicase nsP13 in the unwinding of duplex RNA. Sci. Rep. 10 (2020) 4481. [PMID: 32161317]