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Characterization of a novel archaeal RNA endonuclease from sulfolobus acidocaldarius Russell, Anthony George
Abstract
The study of the mechanisms and components involved in the complex ribosome biogenesis pathway has proven to be challenging, regardless of the organism chosen for analysis. While the strategies and catalytic components required to correctly fold, modify and cleave the pre ribosomal RNAs (rRNA) may differ between organisms from the archaeal, eubacterial or eukaryotic lineages; a unifying feature is the presence of spacer regions flanking the mature sequences which must be removed from the primary rRNA transcript during the maturation process. Some of the RNA nucleases that participate in precursor rRNA cleavages have been identified from several eubacterial and eukaryotic organisms, but those that generate the mature rRNA termini have, for the most part, remained elusive. In the Archaea, little is known about any of the components that are involved in pre rRNA cleavage and maturation. In this study, a novel archaeal RNA endonuclease from the hyperthermophile Sulfolobus acidocaldarius has been identified, characterized and partially purified. The analysis of the nuclease has been based upon its ability to cleave an in vitro synthesized RNA substrate containing the S.acidocaldarius 5' External Transcribed Spacer. The nuclease cleaves the substrate at (or near) positions that correspond to cleavage sites detected within in vivo rRNA precursors. The ability or inability of the enzyme to cleave mutagenized substrates has revealed some of its substrate recognition properties such as its absolute requirement for a purine nucleotide 5' to a cleavable phosphodiester bond. Interestingly, the essential RNA sequence elements recognized by the enzyme are found at the mature 5' end of the 16S rRNA, suggesting a possible in vivo role for the nuclease in mature 5' end formation. The nuclease activity has been partially purified and appears to have a size in excess of 600,000 Daltons. Attempts to obtain highly purified endonuclease activity have proven to be difficult due to the non-abundance, instability and unusual physical properties associated with the enzyme. While the protein constituents have not yet been identified, the activity does not appear to contain an essential RNA component, as was previously reported. The activity may associate with rRNA or ribosomal particles and its substrate requirements and physical characteristics suggest that this nuclease is indeed a novel archaeal endonuclease activity.
Item Metadata
Title |
Characterization of a novel archaeal RNA endonuclease from sulfolobus acidocaldarius
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
2000
|
Description |
The study of the mechanisms and components involved in the complex ribosome
biogenesis pathway has proven to be challenging, regardless of the organism chosen for
analysis. While the strategies and catalytic components required to correctly fold, modify
and cleave the pre ribosomal RNAs (rRNA) may differ between organisms from the
archaeal, eubacterial or eukaryotic lineages; a unifying feature is the presence of spacer
regions flanking the mature sequences which must be removed from the primary rRNA
transcript during the maturation process. Some of the RNA nucleases that participate in
precursor rRNA cleavages have been identified from several eubacterial and eukaryotic
organisms, but those that generate the mature rRNA termini have, for the most part,
remained elusive. In the Archaea, little is known about any of the components that are
involved in pre rRNA cleavage and maturation.
In this study, a novel archaeal RNA endonuclease from the hyperthermophile
Sulfolobus acidocaldarius has been identified, characterized and partially purified. The
analysis of the nuclease has been based upon its ability to cleave an in vitro synthesized
RNA substrate containing the S.acidocaldarius 5' External Transcribed Spacer. The
nuclease cleaves the substrate at (or near) positions that correspond to cleavage sites
detected within in vivo rRNA precursors. The ability or inability of the enzyme to cleave
mutagenized substrates has revealed some of its substrate recognition properties such as
its absolute requirement for a purine nucleotide 5' to a cleavable phosphodiester bond.
Interestingly, the essential RNA sequence elements recognized by the enzyme are found
at the mature 5' end of the 16S rRNA, suggesting a possible in vivo role for the nuclease
in mature 5' end formation.
The nuclease activity has been partially purified and appears to have a size in
excess of 600,000 Daltons. Attempts to obtain highly purified endonuclease activity have
proven to be difficult due to the non-abundance, instability and unusual physical
properties associated with the enzyme. While the protein constituents have not yet been
identified, the activity does not appear to contain an essential RNA component, as was
previously reported. The activity may associate with rRNA or ribosomal particles and its
substrate requirements and physical characteristics suggest that this nuclease is indeed a
novel archaeal endonuclease activity.
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Extent |
10548607 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-07-23
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0099533
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
2000-11
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.