Listeria monocytogenes is a gram positive bacterium and causes many food-borne infections such as Listeriosis. This bacteria is ubiquitous in the environment where it can act as either a saprophyte when free living within the environment or as a pathogen when entering a host organism. Many non-coding RNAs have been identified within the bacteria genome where several of these have been classified as novel non-coding RNAs and may contribute to pathogenesis.[1]
Tiling arrays and mutagenesis identified many non-coding RNAs within the L. monocytogenesgenome and the location of these non-coding RNAs within the bacterial genome was confirmed by RACE (rapid amplification of cDNA ends) analysis. These studies showed that the expression of many non-coding RNAs was dependent on the environment and that several of these non-coding RNAs act as cis-regulatory elements. Comparisons between previously characterized non-coding RNAs and those present in the L. monocyotogenes genome identified 50 novel non-coding RNAs in L. monocyotogenes. An additional comparative study between the pathogenic L. monocytogenes strain and the non pathogenic L. innocua strain identified several non-coding RNAs that are only present within L. monocytogenes which suggests that these ncRNAs may have a role in pathogenesis.[2] The tables below summarizes the location, flanking genes and also the characteristics of the novel small non-coding RNAs identified and the previously characterized non-coding RNAs present in L. monocytogenes
sRNA Antisense to lmo0172 transposase Homolog of rli25 and rli35.
rli24
271029
271186
157
lmo0256
->
->
->
lmo0257
sRNA
rli25
357618
357516
102
lmo0330
->
<-
sRNA Antisense to lmo0330: transposase. Homolog of rli23 and rli35
rli26
388707
388520
187
lmo0360
->
<-
<-
lmo0361
sRNA
rli27
434831
434929
98
lmo0411
<-
->
<-
lmo0412
sRNA
rli28
507394
507206
188
lmo0470
->
<-
->
lmo0471
sRNA Homolog of rli50
rli29
507643
507450
193
lmo0470
->
<-
->
lmo0471
sRNA Antisense to the 5'UTR of lmo0471
rli30
540785
540670
115
lmo0506
->
<-
sRNA Antisense to lmo0506
rli31
597812
597926
114
lmo0558
<-
->
->
lmo0559
Required for lysozyme resistance and pathogenesis.[3] Structure characterized as two long hairpins. Interacts with the RNA binding global regulator SpoVG.[4]
rli32
600750
600604
147
lmo0560
<-
<-
<-
lmo0561
sRNA
rli33
708326
708860
534
lmo0671
->
->
->
lmo0672
sRNA
rli34
803031
802948
83
lmo0777
->
<-
->
lmo0778
sRNA
rli35
855495
855393
102
lmo0828
->
<-
sRNA Antisense to lmo0828: transposase. Homolog of rli23 and rli25
rli36
859527
859444
83
nifJ
->
<-
<-
fbp
sRNA
rli37
907576
907832
256
lmo0866
->
->
->
lmo0867
ORF ORF of 58aa. RBS region: TGATACGGGAGTGTGGTGCTAGTTATG
rli38
1152549
1152917
369
lmo1115
<-
->
->
lmo1116
sRNA role in virulence
rli39
1179807
1179993
187
lmo1149
->
->
<-
lmo1150
sRNA Annotated as a cobalamin riboswitch in Rfam
rli40
1275810
1275547
264
lmo1251
->
<-
<-
lmo1252
ORF ORF of 64 aa. RBS region: AGTGAGGCGTCCTTATG
rli41
1277207
1276713
495
lmo1252
<-
<-
->
lmo1253
Two ORFs ORF of 45 aa. RBS region: AGAGGAGGTATTTTCTATG ORF of 35 aa. RBS region:AAGGAGGAAAACAAATTG
rli42
1399617
1399447
171
lmo1374
->
<-
->
lmo1375
sRNA
rli43
1861630
1861377
253
inlC
<-
<-
<-
rplS
ORF ORF of 35aa. RBS region: AGAGTGAGGTGTAATATG
rli44
2039087
2039375
289
lmo1964
<-
->
<-
lmo1965
ORF ORF of 28aa. RBS region: GGAAAGGATAACCCATG
rli45
2154775
2154852
77
lmo2074
->
->
<-
lmo2075
sRNA Antisense to rli46
rli46
2155058
2154765
294
lmo2074
->
<-
<-
lmo2075
sRNA Antisense to rli45
rli47
2226024
2226532
508
lmo2141
->
->
<-
lmo2142
sRNA
rli48
2361423
2361274
149
lmo2271
<-
<-
->
lmo2272
sRNA
rli49
2660179
2660364
185
lmo2579
->
->
<-
lmo2580
sRNA
rli50
2783274
2783098
176
lmo2709
->
<-
<-
lmo2710
sRNA Homolog of rli28
rli51
207589
207709
120
hly
->
->
->
mpl
5′-UTR-derived Increased in intestinal lumen
rli52
552421
552327
94
lmo0517
<-
<-
<-
lmo0518
5′-UTR-derived Putative riboswitch.
rli53
955829
956001
172
lmo0918
->
->
->
lmo0919
5′-UTR-derived Putative riboswitch.
rli54
1078584
1079111
527
lmo1051
<-
->
->
pdhA
5′-UTR-derived Putative riboswitch.
rli55
1198107
1198389
282
lmo1170
->
->
->
pduQ
5′-UTR-derived Putative riboswitch.
rli56
1199859
1199958
99
pduQ
->
->
->
lmo1172
5′-UTR-derived Putative riboswitch.
rli57
?
1216658
?
lmo1190
->
->
->
cbiA
3′-UTR-derived Annotated as a cobalamin riboswitch in Rfam lmo1190-rli57 transcript levelncreasedinintestinal lumen
^Toledo-Arana A, Dussurget O, Nikitas G, et al. (June 2009). "The Listeria transcriptional landscape from saprophytism to virulence". Nature. 459 (7249): 950–956. doi:10.1038/nature08080. PMID19448609.