Studies on a Vibrio vulnificus functional ortholog of Escherichia coli RNase E imply a conserved function of RNase E-like enzymes in bacteria.
RNase E (Rne) plays a key role in the processing and degradation of RNA in Escherichia coli. In the genome of Vibrio vulnificus, one open reading frame potentially encodes a protein homologous to E. coli RNase E, designated RNase EV, which N-terminal (1-500 amino acids) has 86.4% amino acid identity to the N-terminal catalytic part of RNase E (N-Rne). Here, we report that both the full-length and the N-terminal part of RNase EV (N-RneV) functionally complement E. coli RNase E and their expression consequently supports normal growth of RNase E-depleted E. coli cells. E. coli cells expressing N-RneV showed copy numbers of ColE1-type plasmid similar to that of E. coli cells expressing N-Rne, indicating in vivo ribonucleolytic activity of N-RneV on RNA I, an antisense regulator of ColE1-type plasmid replication. In vitro cleavage assays further showed that N-RneV has cleavage activity and specificity of RNase E on RNase E-targeted sequence of RNA I (BR13). Our findings suggest that RNase E-like proteins have conserved enzymatic properties that determine substrate specificity across species.
Department of Life Science, Chung-Ang University, 221 Hueksok-Dong, Dongjak-Gu, Seoul, 156-756, Republic of Korea.
Minho
M
Lee
Ji-Hyun
JH
Yeom
Che Ok
CO
Jeon
Kangseok
K
Lee
D004261:DNA Replication; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D005816:Genetic Complementation Test; D010957:Plasmids; D012329:RNA, Bacterial / Q000378:metabolism*; D041261:Vibrio vulnificus / Q000201:enzymology* / Q000235:genetics
D012329:RNA, Bacterial; D004722:Endoribonucleases; C022537:ribonuclease E