The role of endonucleases in the expression of ribonuclease II in Escherichia coli.
Ribonuclease II (RNase II), encoded by the rnb gene, is one of the two major Escherichia coli exonucleases involved in mRNA degradation. Some of the ribonucleases implicated in this process have recently been shown to be inter-regulated. In this paper we studied the effects of the endonucleases RNase E and RNase III in rnb expression. We have shown that RNase E cleaves the rnb message internally: when this ribonuclease is inactivated rnb mRNA accumulates with a concomitant increase in RNase II activity. RNase III also affects RNase II expression but in an indirect way. We discuss these implications for the regulation of mRNA degradation.
Zilhão
R
R
Instituto de Biologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
Régnier
P
P
Arraiano
C M
CM
D001483:Base Sequence; D004722:Endoribonucleases / Q000502:physiology*; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins; D005095:Exoribonucleases / Q000235:genetics*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D043244:Ribonuclease III
D029968:Escherichia coli Proteins; D012333:RNA, Messenger; D004722:Endoribonucleases; D005095:Exoribonucleases; C022535:exoribonuclease II; D043244:Ribonuclease III; C468366:ribonuclease III, E coli; C022537:ribonuclease E