dTTP/UTP pyrophosphatase; Nucleoside triphosphate pyrophosphatase that hydrolyzes dTTP and UTP. Can also hydrolyze TTP and the modified nucleotides 5-methyl-UTP (m(5)UTP), pseudo-UTP and 5-methyl-CTP (m(5)CTP). Has weak activity with CTP. May have a dual role in cell division arrest and in preventing the incorporation of modified nucleotides into cellular nucleic acids. Important in maintenance of cell shape.

RNase III; Digests double-stranded RNA formed within single-strand substrates, but not RNA-DNA hybrids. Involved in the processing of rRNA precursors, viral transcripts, some mRNAs and at least 1 tRNA (metY, a minor form of tRNA-init-Met). Cleaves the 30S primary rRNA transcript to yield the immediate precursors to the 16S and 23S rRNAs; cleavage can occur in assembled 30S, 50S and even 70S subunits and is influenced by the presence of ribosomal proteins. The E.coli enzyme does not cleave R.capsulatus rRNA precursor, although R.capsulatus will complement an E.coli disruption, showing s [...]

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 [...]

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.

ssRNA-specific endoribonuclease; Single strand-specific metallo-endoribonuclease involved in late-stage 70S ribosome quality control and in maturation of the 3' terminus of the 16S rRNA. Acts together with the RNase R to eliminate defective 70S ribosomes, but not properly matured 70S ribosomes or individual subunits, by a process mediated specifically by the 30S ribosomal subunit. Involved in the processing of 16S, 23S and 5S rRNAs, with a particularly strong effect on maturation at both the 5'- and 3'- ends of 16S rRNA as well as maturation of the 5'-end of 23S and 5S rRNAs.

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 [...]

RNA pyrophosphohydrolase; Master regulator of 5'-end-dependent mRNA decay. Accelerates the degradation of transcripts by removing pyrophosphate from the 5'-end of triphosphorylated RNA, leading to a more labile monophosphorylated state that can stimulate subsequent ribonuclease cleavage. Preferentially hydrolyzes diadenosine penta-phosphate with ATP as one of the reaction products. Also able to hydrolyze diadenosine hexa- and tetra-phosphate. Has no activity on diadenosine tri-phosphate, ADP-ribose, NADH and UDP-glucose. In an RNase PH (rph) wild-type strain background, RppH is not req [...]

Cell wall structural complex MreBCD transmembrane component MreC; Involved in formation and maintenance of cell shape. Responsible for formation of rod shape. May also contribute to regulation of formation of penicillin-binding proteins. Belongs to the MreC family.

ATP-dependent RNA helicase; DEAD-box RNA helicase involved in RNA degradation. Has RNA- dependent ATPase activity and unwinds double-stranded RNA. Belongs to the DEAD box helicase family. RhlB subfamily.