Spectroscopic characterization of a DNA-binding domain, Z alpha, from the editing enzyme, dsRNA adenosine deaminase: evidence for left-handed Z-DNA in the Z alpha-DNA complex.
Double-stranded RNA adenosine deaminase (ADAR1) is an ubiquitous enzyme in metazoa that edits pre-mRNA changing adenosine to inosine in regions of double-stranded RNA. Zalpha, an N-terminal domain of human ADAR1 encompassing 76 amino acid residues, shows apparent specificity for the left-handed Z-DNA conformation adopted by alternating (dGdC) polymers modified by bromination or methylation, as well as for (dGdC)13 inserts present in supercoiled plasmids. Here, a combination of circular dichroism, fluorescence, and gel-retardation studies is utilized to characterize recombinant Zalpha peptide and to examine its interaction with DNA. Results from laser-Raman spectroscopy experiments provide direct evidence for the existence of Z-DNA in peptide-DNA complexes.
Berger
I
I
Department of Biology, George R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge 02139, USA.
Winston
W
W
Manoharan
R
R
Schwartz
T
T
Alfken
J
J
Kim
Y G
YG
Lowenhaupt
K
K
Herbert
A
A
Rich
A
A
D000243:Adenosine Deaminase / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D003841:Deoxycytidine / Q000737:chemistry; D003849:Deoxyguanosine / Q000737:chemistry; D006358:Hot Temperature; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010455:Peptides / Q000737:chemistry; D011089:Polydeoxyribonucleotides / Q000737:chemistry; D011487:Protein Conformation; D011489:Protein Denaturation; D017393:RNA Editing; D016601:RNA-Binding Proteins; D013050:Spectrometry, Fluorescence; D013059:Spectrum Analysis, Raman
D046911:Macromolecular Substances; D010455:Peptides; D011089:Polydeoxyribonucleotides; D016601:RNA-Binding Proteins; D003841:Deoxycytidine; C019530:poly(dC-dG); D004247:DNA; C567955:ADARB1 protein, human; D000243:Adenosine Deaminase; D003849:Deoxyguanosine