Adenosine-to-inosine (A-to-I) editing is a post-transcriptional modification of RNA which changes its sequence, coding potential and secondary structure. This reaction is catalysed by the adenosine deaminase acting on RNA (ADAR) proteins, ADAR1 and ADAR2 []. ADAR3 (also known as RED2 or ADARB2) prevents the binding of other ADAR enzymes to targets in vitro, and decreases the efficiency of these enzymes. It is capable of binding to both dsRNA and ssRNA. Moreover, ADAR3 lacks editing activity for currently known substrate RNAs, and may have an inactive editase domain. [].ADAR3 contains two double-stranded RNA binding motifs (DSRMs) and a C-terminal RNA-specific adenosine-deaminase (editase) domain. This entry describes the first DSRM.
