DNAmoreDB - A Database of Deoxyribozymes

Published on 1994 in Chem. Biol. volume 1 issue 4.

PubMed ID: 9383394

DOI:10.1016/1074-5521(94)90014-0

Abstract:

BACKGROUND:
Several types of RNA enzymes (ribozymes) have been identified in biological systems and generated in the laboratory. Considering the variety of known RNA enzymes and the similarity of DNA and RNA, it is reasonable to imagine that DNA might be able to function as an enzyme as well. No such DNA enzyme has been found in nature, however. We set out to identify a metal-dependent DNA enzyme using in vitro selection methodology.

RESULTS:
Beginning with a population of 10(14) DNAs containing 50 random nucleotides, we carried out five successive rounds of selective amplification, enriching for individuals that best promote the Pb(2+)-dependent cleavage of a target ribonucleoside 3'-O-P bond embedded within an otherwise all-DNA sequence. By the fifth round, the population as a whole carried out this reaction at a rate of 0.2 min-1. Based on the sequence of 20 individuals isolated from this population, we designed a simplified version of the catalytic domain that operates in an intermolecular context with a turnover rate of 1 min-1. This rate is about 10(5)-fold increased compared to the uncatalyzed reaction.

CONCLUSIONS:
Using in vitro selection techniques, we obtained a DNA enzyme that catalyzes the Pb(2+)-dependent cleavage of an RNA phosphoester in a reaction that proceeds with rapid turnover. The catalytic rate compares favorably to that of known RNA enzymes. We expect that other examples of DNA enzymes will soon be forthcoming.



DNAzymes linked to this article:

Name Isolated sequence Length Reaction
G5_2 GGGGGGAACGCCGTAACAAGCTCTGAACTAGCGGTTGCGATATAGTCGTA      50 RNA cleavage
G5_3 CGGGACTCCGTAGCCCATTGCTTTTTGCAGCGTCAACGAATAGCGTATTA      50 RNA cleavage
G5_4 CCACCATGTCTTCTCGAGCCGAACCGATAGTTACGTCATACCTCCCGTAT      50 RNA cleavage
G5_5 GCCAGATTGCTGCTACCAGCGGTACGAAATAGTGAAGTGTTCGTGACTAT      50 RNA cleavage
G5_6 ATAGGCCATGCTTTGGCTAGCGGCACCGTATAGTGTACCTGCCCTTATCG      50 RNA cleavage
G5_9 TTGCTAGCTCGGCTGAACTTCTGTAGCGCAACCGAAATAGTGAGGCTTGA       51 RNA cleavage
G5_mini* ACACATCTCTGAAGTAGCGCCGCCGTATAGTGACGCTA      38 RNA cleavage
G5_1 TCACACATCTCTGAAGTAGCGCCGCCGTATGTGACGCTAGGGGTTCGCCT      50 RNA cleavage
G5_7 TCTGCTCTCCTCTATTCTAGCAGTGCAGCGAAATATGTCGAATAGTCGGT      50 RNA cleavage
G5_8 TTGCCCAGCATAGTCGGCAGACGTGGTGTTAGCGACACGATAGGCCCGGT      50 RNA cleavage
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