Bleomycin cleaves DNA depending on DNA primary, secondary, and tertiary structures.
The cleavage by bleomycin-Fe(II) complex in the presence of dithiothreitol was investigated by using 3'- or 5'-end-labeled DNA containing the region of the bacteriophage G4 origin of complementary strand synthesis as substrates. Bleomycin cleaved single-stranded DNA substrates preferentially at inverted repeat sequences, which potentially form stem-and-loop structures, in addition to the primary sequence specificity previously reported. DNA sequences preferentially cleaved in the double-stranded substrate were resistant when they lay outside the stem regions. These results suggest the formation of three predicted stem-and-loop structures and other possible secondary structures near the replication origin. Changes of the degree of bleomycin-induced DNA cleavage in a NaCl concentration between 0 and 50 mM suggest that a subtle change of ionic conditions within the double helix, or of DNA conformation, or of both, may occur at 0-50 mM NaCl. Bleomycin appears to be a useful reagent for analyzing secondary and tertiary structures of DNA.
Ueda
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K
Kobayashi
S
S
Komano
T
T
D001483:Base Sequence; D001761:Bleomycin / Q000031:analogs & derivatives; D004247:DNA; D004229:Dithiothreitol; D046911:Macromolecular Substances; D009690:Nucleic Acid Conformation; D013329:Structure-Activity Relationship
D046911:Macromolecular Substances; C023503:iron bleomycin; D001761:Bleomycin; D004247:DNA; D004229:Dithiothreitol