Preferential cleavage of degradative intermediates of rpsT mRNA by the Escherichia coli RNA degradosome.
RNase E, the principal RNase capable of initiating mRNA decay, preferentially attacks 5'-monophosphorylated over 5'-triphosphorylated substrates. Site-specific cleavage in vitro of the rpsT mRNA by RNase H directed by chimeric 2'-O-methyl oligonucleotides was employed to create truncated RNAs which are identical to authentic degradative intermediates. The rates of cleavage of two such intermediates by RNase E in the RNA degradosome are significantly faster (2.5- to 8-fold) than that of intact RNA. This verifies the preference of RNase E for degradative intermediates and can explain the frequent "all-or-none" behavior of mRNAs during the decay process.
Spickler
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Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3.
Stronge
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Mackie
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GA
D004722:Endoribonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D008957:Models, Genetic; D009097:Multienzyme Complexes / Q000378:metabolism*; D009841:Oligonucleotides / Q000378:metabolism; D011117:Polyribonucleotide Nucleotidyltransferase / Q000378:metabolism*; D020365:RNA Helicases / Q000378:metabolism*; D012329:RNA, Bacterial / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism*
D009097:Multienzyme Complexes; D009841:Oligonucleotides; D012329:RNA, Bacterial; D012333:RNA, Messenger; C111244:degradosome; D011117:Polyribonucleotide Nucleotidyltransferase; D004722:Endoribonucleases; D020365:RNA Helicases