Oligoribonuclease; 3'-to-5' exoribonuclease specific for small oligoribonucleotides 2 to 5 nucleotides in length, as well as small (2 to 5 nucleotides) ssDNA oligomers. Probably responsible for the final step in mRNA degradation.

Exoribonuclease R, RNase R; 3'-5' exoribonuclease that releases 5'-nucleoside monophosphates and is involved in maturation of structured RNAs (rRNAs, tRNAs and SsrA/tmRNA). In stationary phase, involved in the post- transcriptional regulation of ompA mRNA stability. Shortens RNA processively to di- and trinucleotides. In vitro, exhibits helicase activity, which is independent of its RNase activity. RNases 2 and R (rnb and this entry) contribute to rRNA degradation during starvation, while RNase R and PNPase (this entry and pnp) are the major contributors to quality control of rRNA duri [...]

Polynucleotide phosphorylase/polyadenylase; Involved in mRNA degradation. Catalyzes the phosphorolysis of single-stranded polyribonucleotides processively in the 3'- to 5'- direction. Also involved, along with RNase II, in tRNA processing. RNases II and R contribute to rRNA degradation during starvation, while RNase R and PNPase are the major contributors to quality control of rRNA during steady state growth.

Endoribonuclease; Endoribonuclease that plays a central role in RNA processing and decay. Required for the maturation of 5S and 16S rRNAs and the majority of tRNAs. Also involved in the degradation of most mRNAs. Can also process other RNA species, such as RNAI, a molecule that controls the replication of ColE1 plasmid, and the cell division inhibitor DicF- RNA. It initiates the decay of RNAs by cutting them internally near their 5'-end. It is able to remove poly(A) tails by an endonucleolytic process. Required to initiate rRNA degradation during both starvation and quality control; ac [...]

RNase BN, tRNA processing enzyme; Zinc phosphodiesterase, which has both exoribonuclease and endoribonuclease activities, depending on the nature of the substrate and of the added divalent cation, and on its 3'-terminal structure. Can process the 3' termini of both CCA-less and CCA-containing tRNA precursors. CCA-less tRNAs are cleaved endonucleolytically after the discriminator base, whereas residues following the CCA sequence can be removed exonucleolytically or endonucleolytically in CCA-containing molecules. Does not remove the CCA sequence. May also be involved in the degradation [...]

Ribonuclease II; Involved in mRNA degradation. Hydrolyzes single-stranded polyribonucleotides processively in the 3' to 5' direction. RNases 2 and R (rnr) contribute to rRNA degradation during starvation, while RNase R and PNPase (pnp) are the major contributors to quality control of rRNA during steady state growth. This RNase is required to decrease expression of RNase PH (rnp) at 42 degrees Celsius during starvation, which in turn represses rRNA degradation. Belongs to the RNR ribonuclease family. RNase II subfamily.

Fused tRNA nucleotidyl transferase/2'3'-cyclic phosphodiesterase/2'nucleotidase and phosphatase; Catalyzes the addition and repair of the essential 3'- terminal CCA sequence in tRNAs without using a nucleic acid template. Adds these three nucleotides in the order of C, C, and A to the tRNA nucleotide-73, using CTP and ATP as substrates and producing inorganic pyrophosphate. Also shows highest phosphatase activity in the presence of Ni(2+) and hydrolyzes pyrophosphate, canonical 5'-nucleoside tri- and diphosphates, NADP, and 2'-AMP with the production of Pi. Displays a metal-independent [...]

Membrane-anchored periplasmic protein involved in septation; Non-essential cell division protein that could be required for efficient cell constriction; Belongs to the DedD family.

poly(A) polymerase; Adds poly(A) tail to the 3' end of many RNAs, which usually targets these RNAs for decay. Plays a significant role in the global control of gene expression, through influencing the rate of transcript degradation, and in the general RNA quality control. Rho-independent transcription terminators may serve as polyadenylation signals. Seems to be involved in plasmid copy number control. Belongs to the tRNA nucleotidyltransferase/poly(A) polymerase family.