A database search for hammerhead ribozyme motifs.
نویسندگان
چکیده
The hammerhead ribozyme is the smallest naturally occurring RNA endonuclease. It is found in subviral plant pathogens and transcripts of satellite DNA from a limited number of organisms. We have performed a database search for novel examples of this catalytic RNA, taking into consideration the recently defined structural requirements for an efficient cleavage under physiological magnesium ion concentrations. In this search, we find, apart from the known examples, several hundreds of motifs in organisms of all kingdoms of life. In a first set of experiments, we analysed hammerhead ribozymes from Arabidopsis thaliana. We found that these sequences are tissue-specifically expressed and that they undergo self-cleavage in planta. Furthermore, their activity under physiological magnesium ion concentrations depends on functional loop-loop interactions, as shown by the lack of activity of appropriate mutants.
منابع مشابه
The Hammerhead Ribozyme: A Long History for a Short RNA.
Small nucleolytic ribozymes are a family of naturally occurring RNA motifs that catalyse a self-transesterification reaction in a highly sequence-specific manner. The hammerhead ribozyme was the first reported and the most extensively studied member of this family. However, and despite intense biochemical and structural research for three decades since its discovery, the history of this model r...
متن کاملSchistosome satellite DNA encodes active hammerhead ribozymes.
Using a computer program designed to search for RNA structural motifs in sequence databases, we have found a hammerhead ribozyme domain encoded in the Smalpha repetitive DNA of Schistosoma mansoni. Transcripts of these repeats are expressed as long multimeric precursor RNAs that cleave in vitro and in vivo into unit-length fragments. This RNA domain is able to engage in both cis and trans cleav...
متن کاملFast cleavage kinetics of a natural hammerhead ribozyme.
The hammerhead ribozyme is a small RNA motif that catalyzes the cleavage and ligation of RNA. The well-studied minimal hammerhead motif is inactive under physiological conditions and requires high Mg(2+) concentrations for efficient cleavage. In contrast, natural hammerheads are active under physiological conditions and contain motifs outside the catalytic core that lower the requirement for Mg...
متن کاملIn vitro and in vivo comparison of hammerhead, hairpin, and hepatitis delta virus self-processing ribozyme cassettes.
Ribozyme expression cassettes were constructed which generate trimmed, trans-acting ribozymes from longer transcripts through the action of a downstream cis-acting ribozyme. This self-processing system produces small, well-defined trans-acting ribozymes with minimal, nonproductive, intramolecular structure. These cassettes also permit direct comparison of different ribozyme expression vectors w...
متن کاملExpanded hammerhead ribozymes containing addressable three-way junctions.
Recently, hammerhead ribozyme (HHR) motifs have been utilized as powerful tools for gene regulation. Here we present a novel design of expanded full-length HHRs that allows attaching additional functionalities to the ribozyme. These features allowed us to construct a very efficient artificial riboswitch in bacteria. Following the design of naturally occurring three-way junctions we attached an ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Biochemical Society transactions
دوره 33 Pt 3 شماره
صفحات -
تاریخ انتشار 2005