IUBMB Enzyme Nomenclature


Accepted name: small RNA 2'-O-methyltransferase

Reaction: S-adenosyl-L-methionine + an [sRNA]-3'-end ribonucleotide = S-adenosyl-L-homocysteine + an [sRNA]-3'-end 2'-O-methylated ribonucleotide

Glossary: sRNA = small RNA

Other name(s): HENMT1 (gene name); HEN1 (gene name)

Systematic name: S-adenosyl-L-methionine:[sRNA]-3'-end ribonucleotide 2'-O-methyltransferase

Comments: The enzyme adds a 2'-O-methyl group to the ribose of the last nucleotide in several types of small RNAs (sRNAs), protecting the 3'-end of sRNAs from uridylation activity and subsequent degradation.

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


1. Park, W., Li, J., Song, R., Messing, J. and Chen, X. CARPEL FACTORY, a Dicer homolog, and HEN1, a novel protein, act in microRNA metabolism in Arabidopsis thaliana. Curr. Biol. 12 (2002) 1484-1495. [PMID: 12225663]

2. Yu, B., Yang, Z., Li, J., Minakhina, S., Yang, M., Padgett, R.W., Steward, R. and Chen, X. Methylation as a crucial step in plant microRNA biogenesis. Science 307 (2005) 932-935. [PMID: 15705854]

3. Kirino, Y. and Mourelatos, Z. 2'-O-methyl modification in mouse piRNAs and its methylase. Nucleic Acids Symp Ser (Oxf) (2007) 417-418. [PMID: 18029764]

4. Huang, Y., Ji, L., Huang, Q., Vassylyev, D.G., Chen, X. and Ma, J.B. Structural insights into mechanisms of the small RNA methyltransferase HEN1. Nature 461 (2009) 823-827. [PMID: 19812675]

5. Peng, L., Zhang, F., Shang, R., Wang, X., Chen, J., Chou, J.J., Ma, J., Wu, L. and Huang, Y. Identification of substrates of the small RNA methyltransferase Hen1 in mouse spermatogonial stem cells and analysis of its methyl-transfer domain. J. Biol. Chem. 293 (2018) 9981-9994. [PMID: 29703750]

[EC created 2022]

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