TY - JOUR
T1 - Selective recognition of pyrimidine motif triplexes by a protein encoded by the bacterial transposon Tn7
AU - Rao, Jason E.
AU - Craig, Nancy L.
N1 - Funding Information:
We are grateful to Dr Paul Miller for all his insight and expertise given to this work, and to Dr Prasad Kuduvalli and Dr David Noll for helpful discussion. We thank Patti Eckhoff and the members of the Craig laboratory for preparation and critical reading of the manuscript. This work was supported by the National Institutes of Health under grant GM53824 to N.L.C.. N.L.C. is an investigator with the Howard Hughes Medical Institute.
PY - 2001/4/13
Y1 - 2001/4/13
N2 - The bacterial transposon Tn7 is distinguished among mobile genetic elements by its targeting abilities. Recently, we reported that Tn7 is able to selectively insert adjacent to triple-helical DNA. The binding of TnsC, a Tn7-encoded protein, to the triplex DNA target leads to the specific transposition of Tn7 adjacent to both inter- and intramolecular pyrimidine motif triplexes. Here, we further probe how Tn7 targets triplex DNA. We report that TnsC discriminates between different types of triplexes, showing binding preference for pyrimidine but not for purine motif intermolecular triplex DNA. The binding preferences of TnsC and the Tn7 insertion profiles were obtained using psoralenated, triplex-forming oligonucleotides annealed to plasmid DNAs. Although the presence of psoralen is not required for targeting nor is it alone able to attract TnsC, we show that the location of psoralen within the pyrimidine motif triplex does alter the position of Tn7 insertion relative to the triplex. Comparison between the triplex-targeting pathway and the highly site-specific targeting pathway mediated by the binding of the Tn7-encoded protein, TnsD, to the unique site attTn7, suggests that similar structural features within each target DNA are recognized by TnsC, leading to site-specific transposition. This work demonstrates that a prokaryotic protein involved in the targeting and regulation of Tn7 translocation, TnsC, can selectively recognize pyrimidine motif triplexes.
AB - The bacterial transposon Tn7 is distinguished among mobile genetic elements by its targeting abilities. Recently, we reported that Tn7 is able to selectively insert adjacent to triple-helical DNA. The binding of TnsC, a Tn7-encoded protein, to the triplex DNA target leads to the specific transposition of Tn7 adjacent to both inter- and intramolecular pyrimidine motif triplexes. Here, we further probe how Tn7 targets triplex DNA. We report that TnsC discriminates between different types of triplexes, showing binding preference for pyrimidine but not for purine motif intermolecular triplex DNA. The binding preferences of TnsC and the Tn7 insertion profiles were obtained using psoralenated, triplex-forming oligonucleotides annealed to plasmid DNAs. Although the presence of psoralen is not required for targeting nor is it alone able to attract TnsC, we show that the location of psoralen within the pyrimidine motif triplex does alter the position of Tn7 insertion relative to the triplex. Comparison between the triplex-targeting pathway and the highly site-specific targeting pathway mediated by the binding of the Tn7-encoded protein, TnsD, to the unique site attTn7, suggests that similar structural features within each target DNA are recognized by TnsC, leading to site-specific transposition. This work demonstrates that a prokaryotic protein involved in the targeting and regulation of Tn7 translocation, TnsC, can selectively recognize pyrimidine motif triplexes.
KW - Psoralen
KW - Target site selection
KW - Transposition
KW - Triple helical DNA
KW - Triplex-binding protein
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U2 - 10.1006/jmbi.2001.4553
DO - 10.1006/jmbi.2001.4553
M3 - Article
C2 - 11292332
AN - SCOPUS:0035853286
SN - 0022-2836
VL - 307
SP - 1161
EP - 1170
JO - Journal of molecular biology
JF - Journal of molecular biology
IS - 5
ER -