RNA recognition by the ADAR2 dsRBMs
| Authors | |
|---|---|
| Year of publication | 2006 |
| Type | Article in Proceedings |
| Conference | Meeting of Internationat Resarch Scholars |
| MU Faculty or unit | |
| Citation | |
| Field | Biochemistry |
| Keywords | RNA modification; RNA binding; structure; nuclear magnetic resonance |
| Description | Adenosine deaminases that act on RNA (ADARs) tune and regulate gene expression. Although ADARs act mostly as nonspecific enzymes, they can recode certain genes in a highly specific manner. This results from preferential binding of the ADARs to certain RNA substrates. To understand how ADARs bind RNA, we investigated the N-terminal region of ADAR2 by nuclear magnetic resonance (NMR) spectroscopy. This region is responsible for RNA binding and consists of the two double-stranded RNA-binding motifs (dsRBMs). We determined the structure of these two dsRBMs and carried out an NMR chemical shift perturbation study of the interaction of the two dsRBMs with a 71 nucleotide RNA encoding the R/G site of the GluR-B. Based on our precise identification of both the protein and RNA interaction surfaces, we built an NMR-derived model of the ADAR2 dsRBMs in complex with the R/G stem-loop RNA. We showed that each dsRBM binds a different structural element of the R/G stem-loop; dsRBM1 binds a stem capped by a pentaloop and dsRBM2 recognizes a stem containing two AC mismatches. The importance of RNA irregularities for the preferential binding by ADAR2 dsRBMs was confirmed by in vitro mutagenesis studies in both the protein and the RNA. Our structural and functional studies demonstrate that the ADAR2 dsRBMs have the ability to discriminate specific structural features of RNA suggesting their importance for the editing site selectivity. |
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