TY - JOUR
T1 - Hairpin DNA sequences bound strongly by bleomycin exhibit enhanced double-strand cleavage
AU - Roy, Basab
AU - Hecht, Sidney
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/3/19
Y1 - 2014/3/19
N2 - Clinically used bleomycin A5 has been employed in a study of double-strand cleavage of a library of 10 hairpin DNAs originally selected on the basis of their strong binding to bleomycin. Each of the DNAs underwent double-strand cleavage at more than one site, and all of the cleavage sites were within, or in close proximity to, an eight-base-pair region of the duplex that had been randomized to create the original library. A total of 31 double-strand cleavage sites were identified on the 10 DNAs, and 14 of these sites were found to represent coupled cleavage sites, that is, events in which one of the two strands was always cleaved first, followed by the associated site on the opposite strand. Most of these coupled sites underwent cleavage by a mechanism described previously by the Povirk laboratory and afforded cleavage patterns entirely analogous to those reported. However, at least one coupled cleavage event was noted that did not conform to the pattern of those described previously. More surprisingly, 17 double-strand cleavages were found not to result from coupled double-strand cleavage, and we posit that these cleavages resulted from a new mechanism not previously described. Enhanced double-strand cleavages at these sites appear to be a consequence of the dynamic nature of the interaction of Fe·BLM A5 with the strongly bound hairpin DNAs.
AB - Clinically used bleomycin A5 has been employed in a study of double-strand cleavage of a library of 10 hairpin DNAs originally selected on the basis of their strong binding to bleomycin. Each of the DNAs underwent double-strand cleavage at more than one site, and all of the cleavage sites were within, or in close proximity to, an eight-base-pair region of the duplex that had been randomized to create the original library. A total of 31 double-strand cleavage sites were identified on the 10 DNAs, and 14 of these sites were found to represent coupled cleavage sites, that is, events in which one of the two strands was always cleaved first, followed by the associated site on the opposite strand. Most of these coupled sites underwent cleavage by a mechanism described previously by the Povirk laboratory and afforded cleavage patterns entirely analogous to those reported. However, at least one coupled cleavage event was noted that did not conform to the pattern of those described previously. More surprisingly, 17 double-strand cleavages were found not to result from coupled double-strand cleavage, and we posit that these cleavages resulted from a new mechanism not previously described. Enhanced double-strand cleavages at these sites appear to be a consequence of the dynamic nature of the interaction of Fe·BLM A5 with the strongly bound hairpin DNAs.
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U2 - 10.1021/ja500414a
DO - 10.1021/ja500414a
M3 - Article
C2 - 24548300
AN - SCOPUS:84896505257
VL - 136
SP - 4382
EP - 4393
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 11
ER -