mRNA degradation in Escherichia coli: a novel factor which impedes the exoribonucleolytic activity of PNPase at stem-loop structures.
Stem-loop structures can protect upstream mRNA from degradation by impeding the processive activities of 3'-5' exoribonucleases. The ability of such structures to impede exonuclease activity in vitro is insufficient to account for the stability they can confer on mRNA in vivo. In this study we identify a factor from Escherichia coli which specifically impedes the processive activity of the 3'-5' exonuclease PNPase at stem-loop structures in vitro. This factor can, potentially, reconcile the apparent discrepancy between the ability of 3' stem-loop structures to stabilize upstream mRNA in vitro and in vivo. Its mechanism of action, and possible role in regulating mRNA degradation, is discussed.
Causton
H
H
Imperial Cancer Research Fund Laboratories, Institute of Molecular Medicine, Oxford, UK.
Py
B
B
McLaren
R S
RS
Higgins
C F
CF
D001426:Bacterial Proteins / Q000378:metabolism; D001483:Base Sequence; D003432:Cross-Linking Reagents; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D011117:Polyribonucleotide Nucleotidyltransferase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism
D001426:Bacterial Proteins; D003432:Cross-Linking Reagents; D004269:DNA, Bacterial; D012329:RNA, Bacterial; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011117:Polyribonucleotide Nucleotidyltransferase