DOUBLE-STRANDED RNA-SPECIFIC ADENOSINE-DEAMINASE - NUCLEIC-ACID BINDING-PROPERTIES

The RNA-specific adenosine deaminase (ADAR1, herein referred to as ADA R) is an interferon-inducible RNA-editing enzyme. ADAR catalyzes the C -6 deamination of adenosine in double-stranded (ds) structures present in viral RNAs and cellular pre-mRNAs as well as synthetic dsRNA subst rates. ADAR possesses three functionally distinct copies of the highly conserved double-stranded RNA binding R motif (R-I, R-II, R-III) impl icated in the recognition of dsRNA structures within the substrate RNA s. ADAR is also a Z-DNA-binding protein. Two Z-DNA binding motifs (Z a lpha and Z beta) present in ADAR correspond to repeated regions homolo gous to the N-terminal region of the vaccinia virus E3L protein. Here we describe assay methods for measurement of ADAR enzymatic activity, dsRNA binding activity, and Z-DNA binding activity. (C) 1998 Academic Press.