Involvement of RNase G in in vivo mRNA metabolism in Escherichia coli.
BACKGROUND
Escherichia coli rng gene (previously called cafA) encodes a novel RNase, named RNase G, which is involved in the 5' end-processing of 16S rRNA. In rng mutant cells, a precursor form of 16S rRNA, 16.3S rRNA, is accumulated. Here we report a role of RNase G in the in vivo mRNA metabolism.


RESULTS
We found that rng:cat mutant strains overproduced a protein of about 100 kDa. N-terminal amino acid sequencing of this protein showed that it was identical to the fermentative alcohol dehydrogenase, the product of the adhE gene located at 28 min on the E. coli genetic map. The level of adhE mRNA was significantly higher in the rng:cat mutant strain than that in its parental strain, while such differences were not seen in other genes we examined. A rifampicin-chase experiment revealed that the half-life of adhE mRNA was 2.5-fold longer in the rng:cat disruptant than in the wild-type.


CONCLUSIONS
These results indicate that, in addition to rRNA processing, RNase G is involved in in vivo mRNA degradation in E. coli.
Umitsuki
G
G
Department of Bioengineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.
Wachi
M
M
Takada
A
A
Hikichi
T
T
Nagai
K
K
D000426:Alcohol Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D004722:Endoribonucleases / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D007763:Lac Operon; D009154:Mutation; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012322:RNA Precursors / Q000235:genetics; D012323:RNA Processing, Post-Transcriptional; D012329:RNA, Bacterial / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D012293:Rifampin / Q000378:metabolism
D029968:Escherichia coli Proteins; D012322:RNA Precursors; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012336:RNA, Ribosomal, 16S; D011993:Recombinant Fusion Proteins; D000426:Alcohol Dehydrogenase; D004722:Endoribonucleases; C081905:rng protein, E coli; D012293:Rifampin