Table 1.

Proteins involved in post-transcriptional RNA metabolism in E. coli.

Name	Gene	Mode of Action	Substrate Preference	Functions*
RNase E	rne	Endonuclease	Single-stranded RNA	mRNA decay, tRNA processing, rRNA processing, sRNA degradation
RNase III	rnc	Endonuclease	Double-stranded RNA	rRNA processing, mRNA decay, sRNA degradation
RNase P	rnpA, rnpB	Endonuclease	Single-stranded RNA	tRNA processing, mRNA decay, rRNA processing
RNase G	rng	Endonuclease	Single-stranded RNA	rRNA processing, mRNA decay, tRNA processing
YbeY	ybeY	Endonuclease	Single-stranded RNA	rRNA processing
RNase Z/BN	rnz	Endonuclease/3′ → 5′ exonuclease	Single-stranded RNA	mRNA decay, tRNA processing
RNase LS	rnlA	Endonuclease	Single-stranded RNA	mRNA decay
RNase T	rnt	3′ → 5′ exonuclease	Single-stranded RNA	tRNA processing, rRNA processing
RNase PH	rph	3′ → 5′ exonuclease	Single-stranded RNA	tRNA processing
RNase D	rnd	3′ → 5′ exonuclease	Single-stranded RNA	tRNA processing
PNPase	pnp	3′ → 5′ exonuclease	Single-stranded RNA	mRNA decay, sRNA degradation, tRNA processing
RNase II	rnb	3′ → 5′ exonuclease	Single-stranded RNA	mRNA decay, tRNA processing
RNase R	rnr	3′ → 5′ exonuclease	Single-stranded RNA	rRNA processing, sRNA degradation
Oligoribonuclease	orn	3′ → 5′ exonuclease	Single-stranded RNA	mRNA decay
Poly(A) polymerase	pcnB	polymerase	Single-stranded RNA	mRNA decay, tRNA maturation
Hfq	hfq	RNA binding protein	Single-stranded RNA	mRNA decay, polyadenylation, sRNA metabolism
tRNA nucleotidyl transferase	cca	polymerase	tRNAs	tRNA maturation
RNA diphosphohydrolase	rppH	phosphatase	5′ triphosphate or 5′ diphosphate	mRNA decay
RhlB	rhlB	Helicase	Double-stranded RNA	mRNA decay
RhlE	rhlE	Helicase	Double-stranded RNA	mRNA decay
SrmB	srmB	Helicase	Double-stranded RNA	mRNA decay
CsdA	csdA	Helicase	Double-stranded RNA	mRNA decay under low temperature
DbpA	dbpA	Helicase	Double-stranded RNA	Ribosome biogenesis
Enolase	eno	Enolase	?	RNA metabolism ?
MazF	mazF	mRNA interferase	Single-stranded RNA	mRNA decay, stress management
RelE	relE	mRNA interferase	Single-stranded RNA	mRNA decay, stress management
HicA	hicA	mRNA interferase	Single-stranded RNA	mRNA decay, stress management
Colicin E5		tRNA targeting enzyme	Single-stranded RNA	Stress management
Colicin D		tRNA targeting enzyme	Single-stranded RNA	Stress management
Colicin E3		tRNA targeting enzyme	Single-stranded RNA	Stress management
Cas6A	cas6	Endonuclease	Single-stranded RNA	Immune defense

^*Listed in order of the importance of the enzyme

?: Role of enolase in RNA metabolism is yet to be defined.