Allosteric Hammerhead Ribozyme TRAPs
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- 作者：Donald H. Burke ; Nicole D. S. Ozerova ; and Marit Nilsen-Hamilton
- 刊名：Biochemistry
- 出版年：2002
- 出版时间：May 28, 2002
- 年：2002
- 卷：41
- 期：21
- 页码：6588 - 6594
- 全文大小：155K
- 年卷期：v.41,no.21(May 28, 2002)
- ISSN：1520-4995
文摘
A new mode of allosteric regulation of nucleic acid enzymes is described and shown to operateeffectively with hammerhead ribozymes. In the "TRAP" design (for targeted ribozyme-attenuated probe),a 3' terminal "attenuator" anneals to conserved bases in the catalytic core to form the "off" state of theribozyme. Binding of RNA or DNA to an antisense sequence linking the ribozyme and attenuator freesthe core to fold into an active conformation, even though the antisense sequence itself does not interferewith the ribozyme. TRAP hammerheads based on the previously characterized HH8 ribozyme were shownto be activated more than 250-fold upon addition of the sense strand. RNA oligonucleotides were moreeffective activators than DNA oligos, consistent with the known relative helix stabilities (RNA-RNA >RNA-DNA). Oligonucleotides that directly paired with the attenuator gave up to 1760-fold activation.The magnitude of the activation was greater when the oligo was added prior to folding than if it wasadded during the cleavage reaction. The TRAP design requires no prior knowledge of (deoxy)ribozymestructure beyond identification of the essential core. Thus, this approach should be readily generalizableto other systems for biomedicine, sensor technology, and additional applications.