Metal ion recognition of the metal-binding motif in hammerhead ribozymes
نویسندگان
چکیده
منابع مشابه
Physicochemical analysis of the interaction between a metal ion and the metal-ion-binding motif in hammerhead ribozymes.
Hammerhead ribozymes have a metal-ion-binding motif in the conserved core region, and this motif can capture several kinds of metal ions. In order to determine what kind of metal ions can be recognized by the motif, we measured 2D 1H-1H NOESY spectra in the presence of various metal ions, such as Cd2+, Na+ and Co(NH3)6(3+) ions, as well as in the absence of these ions. We have completed the ass...
متن کاملObservations on catalysis by hammerhead ribozymes are consistent with a two-divalent-metal-ion mechanism.
Significant cleavage by hammerhead ribozymes requires activation by divalent metal ions. Several models have been proposed to account for the influence of metal ions on hammerhead activity. A number of recent papers have presented data that have been interpreted as supporting a one-metal-hydroxide-ion mechanism. In addition, a solvent deuterium isotope effect has been taken as evidence against ...
متن کاملEnhancement of the cleavage rates of DNA-armed hammerhead ribozymes by various divalent metal ions.
In order to characterize structure-function relationships, the kinetic behavior of chimeric RNA/DNA ribozyme was compared with that of all RNA ribozyme. Determined kcat values were proven to represent the chemical-cleavage step and not the product-dissociation step. In agreement with the finding by Dahm and Uhlenbeck [Biochemistry 30, 9464-9469 (1991)], various metal ions, including Co2+ and Ca...
متن کاملHammerhead ribozymes: true metal or nucleobase catalysis? Where is the catalytic power from?
The hammerhead ribozyme was first considered as a metalloenzyme despite persistent inconsistencies between structural and functional data. In the last decade, metal ions were confirmed as catalysts in self-splicing ribozymes but displaced by nucleobases in self-cleaving ribozymes. However, a model of catalysis just relying on nucleobases as catalysts does not fully fit some recent data. Gatheri...
متن کاملFrom nucleotides to ribozymes – a comparison of their metal ion binding properties
It is undisputable that the fates of metal ions and nucleic acids are inescapably interwoven. Metal ions are essential for charge compensation of the negatively charged phosphate–sugar backbone, they are instrumental for proper folding, and last but not least they are crucial cofactors for ribozyme catalysis. Considerable progress has been achieved in the past few years on the identification of...
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ژورنال
عنوان ژورنال: Seibutsu Butsuri
سال: 2003
ISSN: 0582-4052,1347-4219
DOI: 10.2142/biophys.43.s28_5