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Namehelp_outline
a 3'-end uridylyl-adenosine-RNA
Identifier
RHEA-COMP:17386
Reactive part
help_outline
- Name help_outline 3'-terminal pUpA residue Identifier CHEBI:176518 Charge -2 Formula C19H22N7O14P2 SMILEShelp_outline C1=CC(NC(N1[C@@H]2O[C@H](COP(*)(=O)[O-])[C@H]([C@H]2O)OP(=O)([O-])OC[C@H]3O[C@@H](N4C=5C(N=C4)=C(N=CN5)N)[C@@H]([C@@H]3O)O)=O)=O 2D coordinates Mol file for the small molecule Search links Involved in 1 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
a 3'-end 2',3'-cyclophospho-uridine-RNA
Identifier
RHEA-COMP:17385
Reactive part
help_outline
- Name help_outline 3'-terminal uridine 2',3'-cyclic phosphate residue Identifier CHEBI:85644 Charge -2 Formula C9H9N2O10P2 SMILEShelp_outline [O-]P(-*)(=O)OC[C@H]1O[C@H]([C@@H]2OP([O-])(=O)O[C@H]12)n1ccc(=O)[nH]c1=O 2D coordinates Mol file for the small molecule Search links Involved in 3 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline adenosine Identifier CHEBI:16335 (CAS: 58-61-7) help_outline Charge 0 Formula C10H13N5O4 InChIKeyhelp_outline OIRDTQYFTABQOQ-KQYNXXCUSA-N SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](CO)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 21 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:67896 | RHEA:67897 | RHEA:67898 | RHEA:67899 | |
|---|---|---|---|---|
| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
| UniProtKB help_outline |
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Publications
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Structural and mechanistic basis for preferential deadenylation of U6 snRNA by Usb1.
Nomura Y., Roston D., Montemayor E.J., Cui Q., Butcher S.E.
Post-transcriptional modification of snRNA is central to spliceosome function. Usb1 is an exoribonuclease that shortens the oligo-uridine tail of U6 snRNA, resulting in a terminal 2',3' cyclic phosphate group in most eukaryotes, including humans. Loss of function mutations in human Usb1 cause the ... >> More
Post-transcriptional modification of snRNA is central to spliceosome function. Usb1 is an exoribonuclease that shortens the oligo-uridine tail of U6 snRNA, resulting in a terminal 2',3' cyclic phosphate group in most eukaryotes, including humans. Loss of function mutations in human Usb1 cause the rare disorder poikiloderma with neutropenia (PN), and result in U6 snRNAs with elongated 3' ends that are aberrantly adenylated. Here, we show that human Usb1 removes 3' adenosines with 20-fold greater efficiency than uridines, which explains the presence of adenylated U6 snRNAs in cells lacking Usb1. We determined three high-resolution co-crystal structures of Usb1: wild-type Usb1 bound to the substrate analog adenosine 5'-monophosphate, and an inactive mutant bound to RNAs with a 3' terminal adenosine and uridine. These structures, along with QM/MM MD simulations of the catalytic mechanism, illuminate the molecular basis for preferential deadenylation of U6 snRNA. The extent of Usb1 processing is influenced by the secondary structure of U6 snRNA. << Less
Nucleic Acids Res. 46:11488-11501(2018) [PubMed] [EuropePMC]