Substrate analogs that trap the 2′-phospho-ADP-ribosylated RNA intermediate of the Tpt1 (tRNA 2′-phosphotransferase) reaction pathway Journal Article
| Authors: | Dantuluri, S.; Abdullahu, L.; Munir, A.; Katolik, A.; Damha, M. J.; Shuman, S. |
| Article Title: | Substrate analogs that trap the 2′-phospho-ADP-ribosylated RNA intermediate of the Tpt1 (tRNA 2′-phosphotransferase) reaction pathway |
| Abstract: | The enzyme Tpt1 removes an internal RNA 2′-PO4 via a two-step reaction in which: (i) the 2′-PO4 attacks NAD+ to form an RNA-2′-phospho-(ADP-ribose) intermediate and nicotinamide; and (ii) transesterification of the ADP-ribose O2′′ to the RNA 2′-phosphodiester yields 2′-OH RNA and ADP-ribose-1′′,2′′-cyclic phosphate. Because step 2 is much faster than step 1, the ADP-ribosylated RNA intermediate is virtually undetectable under normal circumstances. Here, by testing chemically modified nucleic acid substrates for activity with bacterial Tpt1 enzymes, we find that replacement of the ribose-2′-PO4 nucleotide with arabinose-2′-PO4 selectively slows step 2 of the reaction pathway and results in the transient accumulation of high levels of the reaction intermediate. We report that replacing the NMN ribose of NAD+ with 2′-fluoroarabinose (thereby eliminating the ribose O2′′ nucleophile) results in durable trapping of RNA-2′-phospho-(ADP-fluoroarabinose) as a "dead-end" product of step 1. Tpt1 enzymes from diverse taxa differ in their capacity to use ara-2′′FNAD+ as a substrate. © 2020 Dantuluri et al. |
| Keywords: | transesterification; nicotinamide adenine dinucleotide; adp-ribosylation; rna 2′-phosphotransferase |
| Journal Title: | RNA |
| Volume: | 26 |
| Issue: | 4 |
| ISSN: | 1355-8382 |
| Publisher: | Cold Spring Harbor Laboratory Press |
| Date Published: | 2020-04-01 |
| Start Page: | 373 |
| End Page: | 381 |
| Language: | English |
| DOI: | 10.1261/rna.074377.119 |
| PUBMED: | 31932322 |
| PROVIDER: | scopus |
| PMCID: | PMC7075268 |
| DOI/URL: | |
| Notes: | Article -- Export Date: 1 April 2020 -- Source: Scopus |
Altmetric
Citation Impact
BMJ Impact Analytics
Related MSK Work