TSR3 transfers aminocarboxypropyl group from S-adenosylmethionine to N(1)-methylpseudouridine-1248 of 18SE rRNA yielding N(1)-methyl-N(3)-aminocarboxypropylpseudouridine-1248

Stable Identifier
Reaction [transition]
Homo sapiens
Locations in the PathwayBrowser
SVG |   | PPTX  | SBGN
Click the image above or here to open this reaction in the Pathway Browser
The layout of this reaction may differ from that in the pathway view due to the constraints in pathway layout
In the cytoplasm TSR3 transfers an aminocarboxypropyl group from S-adenosylmethionine (AdoMet) to the N(3) position of N(1)-methylpseudouridine at nucleotide 1248 of 18S rRNA yielding N(1)-methyl-N(3)-aminocarboxylpropylpseudouridine-1248 (Meyer et al. 2016). Prior to this reaction, the SNORA13 or ACA13 H/ACA snoRNP (homologue of the snR35 snoRNP in yeast) in the nucleus converts uridine-1248 to pseudouridine-1248 and the EMG1 component of the small subunit processome in the nucleus methylates the N(1) position of pseudouridine-1248. The 18SE precursor of 18S rRNA containing N(1)-methylpseudouridine is then exported to the cytosol as part of the 40S pre-ribosomal subunit. TSR3 is believed to act on the 18SE precursor rather than the mature 18S rRNA because interference with the activity of TSR3 results in an accumulation of 18SE precursor (Meyer et al. 2016).
Literature References
PubMed ID Title Journal Year
27084949 Ribosome biogenesis factor Tsr3 is the aminocarboxypropyl transferase responsible for 18S rRNA hypermodification in yeast and humans

Kötter, P, Wurm, JP, Wöhnert, J, Pogoryelov, D, Sharma, S, Immer, C, Meyer, B, Entian, KD, Lafontaine, DL

Nucleic Acids Res. 2016
Catalyst Activity

transferase activity of TSR3 [cytosol]

Cite Us!