Dual function of RNase E for control of M1 RNA biosynthesis in Escherichia coli.
M1 RNA, the gene product of rnpB, is the catalytic subunit of RNase P in Escherichia coli. M1 RNA is transcribed from a proximal promoter as pM1 RNA, a precursor M1 RNA, and then is processed at its 3' end by RNase E. In addition to pM1 RNA, large rnpB-containing transcripts are produced from unknown upstream promoters. However, it is not known yet how these large transcripts contribute to M1 RNA biosynthesis. To examine their biological relevance to M1 RNA biosynthesis, we constructed a model upstream transcript, upRNA, and analyzed its cellular metabolism. We found that upRNA was primarily degraded rather than processed to M1 RNA in the cell and that this degradation occurred in RNase E-dependent manner. The in vitro cleavage assay with the N-terminal catalytic fraction of RNase E showed that the M1 RNA structural sequence in upRNA was much more vulnerable to the enzyme than the sequence in pM1 RNA. Considering that RNase E is a processing enzyme involved in 3' end formation of M1 RNA, our results imply that this enzyme plays a dual role in processing and degradation to achieve tight control of M1 RNA biosynthesis.
Ko
Jae-hyeong
JH
Department of Chemistry and Center for Molecular Design and Synthesis, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
Han
Kook
K
Kim
Yool
Y
Sim
Soyeong
S
Kim
Kwang-sun
KS
Lee
Sang-Joon
SJ
Cho
Bongrae
B
Lee
Kangryul
K
Lee
Younghoon
Y
D004722:Endoribonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000096:biosynthesis* / Q000737:chemistry; D015964:Gene Expression Regulation, Bacterial; D008954:Models, Biological; D009690:Nucleic Acid Conformation; D020871:RNA Stability; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D043262:Ribonuclease P / Q000096:biosynthesis* / Q000737:chemistry; D013379:Substrate Specificity
D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D004722:Endoribonucleases; D043262:Ribonuclease P; C470865:ribonuclease P, E coli; C022537:ribonuclease E