Abstract
The RNA-editing adenosine deaminases (ADARs) catalyze deamination of adenosine to inosine in double stranded structure found in various RNA substrates, including mRNAs. Here we describe the synthesis of a phosphoramidite of 2′-deoxy-2′-mercaptoadenosine and its incorporation into an ADAR substrate. Surprisingly, no deamination product was observed with this substrate indicating replacing the 2′-OH with a 2′-SH at the editing site is highly inhibitory. Modeling of nucleotide binding into the active site suggests the side chain of T375 of human ADAR2 to be in proximity of the 2 ′-substituent. Mutation of this residue to cysteine caused a greater that 100-fold reduction in deamination rate with the 2 ′-OH substrate.
Original language | English (US) |
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Pages (from-to) | 78-88 |
Number of pages | 11 |
Journal | Nucleosides, Nucleotides and Nucleic Acids |
Volume | 28 |
Issue number | 2 |
DOIs | |
State | Published - Feb 2009 |
Keywords
- ADARs
- Nucleotide binding
- RNA substrates
ASJC Scopus subject areas
- Genetics
- Biochemistry
- Molecular Medicine