Crystal structure of the Zalpha domain of the human editing enzyme ADAR1 bound to left-handed Z-DNA.
The editing enzyme double-stranded RNA adenosine deaminase includes a DNA binding domain, Zalpha, which is specific for left-handed Z-DNA. The 2.1 angstrom crystal structure of Zalpha complexed to DNA reveals that the substrate is in the left-handed Z conformation. The contacts between Zalpha and Z-DNA are made primarily with the "zigzag" sugar-phosphate backbone, which provides a basis for the specificity for the Z conformation. A single base contact is observed to guanine in the syn conformation, characteristic of Z-DNA. Intriguingly, the helix-turn-helix motif, frequently used to recognize B-DNA, is used by Zalpha to contact Z-DNA.
Schwartz
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Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Rould
M A
MA
Lowenhaupt
K
K
Herbert
A
A
Rich
A
A
D000243:Adenosine Deaminase / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D019077:Helix-Turn-Helix Motifs; D006801:Humans; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D016601:RNA-Binding Proteins; D013379:Substrate Specificity; D014867:Water / Q000378:metabolism
D016601:RNA-Binding Proteins; D014867:Water; D004247:DNA; C567955:ADARB1 protein, human; D000243:Adenosine Deaminase