TY - JOUR
T1 - A Conformationally Restricted Guanosine Analog Reveals the Catalytic Relevance of Three Structures of an RNA Enzyme
AU - Yajima, Rieko
AU - Proctor, David J.
AU - Kierzek, Ryszard
AU - Kierzek, Elzbieta
AU - Bevilacqua, Philip C.
N1 - Funding Information:
We would like to acknowledge the following agencies for generous support: American Chemical Society-Petroleum Research Fund and National Science Foundation grant MCB-0527102 (P.C.B.), National Institutes of Health grant #1R03TW1068 (R.K. and D.H. Turner), and the Natural Sciences and Engineering Research Council of Canada for a post-graduate scholarship (R.Y.). We also would like to thank Katsu Murakami for assistance in preparing Figure 4 , and Steve Benkovic, Barbara Golden, Sharon Hammes-Schiffer, and Doug Turner for suggestions on the manuscript. We dedicate this paper to Doug Turner on the occasion of his 60 th birthday.
PY - 2007/1
Y1 - 2007/1
N2 - Recent studies indicate that RNA function can be enhanced by the incorporation of conformationally restricted nucleotides. Herein, we use 8-bromoguanosine, a nucleotide analog with an enforced syn conformation, to elucidate the catalytic relevance of ribozyme structures. We chose to study the lead-dependent ribozyme (leadzyme) because structural models derived from NMR, crystal, and computational (MC-Sym) studies differ in which of the three active site guanosines (G7, G9, or G24) have a syn glycosidic torsion angle. Kinetic assays were carried out on 8BrG variants at these three guanosine positions. These data indicate that an 8BrG24 leadzyme is hyperactive, while 8BrG7 and 8BrG9 leadzymes have reduced activity. These findings support the computational model of the leadzyme, rather than the NMR and crystal structures, as being the most relevant to phosphodiester bond cleavage.
AB - Recent studies indicate that RNA function can be enhanced by the incorporation of conformationally restricted nucleotides. Herein, we use 8-bromoguanosine, a nucleotide analog with an enforced syn conformation, to elucidate the catalytic relevance of ribozyme structures. We chose to study the lead-dependent ribozyme (leadzyme) because structural models derived from NMR, crystal, and computational (MC-Sym) studies differ in which of the three active site guanosines (G7, G9, or G24) have a syn glycosidic torsion angle. Kinetic assays were carried out on 8BrG variants at these three guanosine positions. These data indicate that an 8BrG24 leadzyme is hyperactive, while 8BrG7 and 8BrG9 leadzymes have reduced activity. These findings support the computational model of the leadzyme, rather than the NMR and crystal structures, as being the most relevant to phosphodiester bond cleavage.
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U2 - 10.1016/j.chembiol.2006.11.004
DO - 10.1016/j.chembiol.2006.11.004
M3 - Article
C2 - 17254949
AN - SCOPUS:33846304310
SN - 1074-5521
VL - 14
SP - 23
EP - 30
JO - Chemistry and Biology
JF - Chemistry and Biology
IS - 1
ER -