Details on the RNA modification alphabet used by the Modstrings package
Modstrings 1.24.0
The alphabets for the modifications used in this package are based on the compilation of RNA modifications by the Bujnicki lab (Boccaletto et al. 2018). The alphabet was modified to remove some incompatible characters.
If modifications are missing, let us know.
| modification | short name | nomenclature | orig. base | abbreviation | 
|---|---|---|---|---|
| 1,2’-O-dimethyladenosine | m1Am | 01A | A | œ | 
| 1,2’-O-dimethylguanosine | m1Gm | 01G | G | ε | 
| 1,2’-O-dimethylinosine | m1Im | 019A | A | ξ | 
| 1-methyl-3-(3-amino-3-carboxypropyl)pseudouridine | m1acp3Y | 1309U | U | α | 
| 1-methyladenosine | m1A | 1A | A | " | 
| 1-methylguanosine | m1G | 1G | G | K | 
| 1-methylinosine | m1I | 19A | A | O | 
| 1-methylpseudouridine | m1Y | 19U | U | ] | 
| 2,8-dimethyladenosine | m2,8A | 28A | A | ± | 
| 2-geranylthiouridine | ges2U | 21U | U | Γ | 
| 2-lysidine | k2C | 21C | C | } | 
| 2-methyladenosine | m2A | 2A | A | / | 
| 2-methylthiomethylenethio-N6-isopentenyl-adenosine | msms2i6A | 2361A | A | £ | 
| 2-methylthio-cyclic-N6-threonylcarbamoyladenosine | ms2ct6A | 2164A | A | ÿ | 
| 2-methylthio-N6-(cis-hydroxyisopentenyl)-adenosine | ms2io6A | 2160A | A | ≠ | 
| 2-methylthio-N6-hydroxynorvalylcarbamoyladenosine | ms2hn6A | 2163A | A | ≈ | 
| 2-methylthio-N6-isopentenyladenosine | ms2i6A | 2161A | A | * | 
| 2-methylthio-N6-methyladenosine | ms2m6A | 621A | A | ∞ | 
| 2-methylthio-N6-threonylcarbamoyladenosine | ms2t6A | 2162A | A | [ | 
| 2-selenouridine | se2U | 20U | U | ω | 
| 2-thio-2’-O-methyluridine | s2Um | 02U | U | ∏ | 
| 2-thiocytidine | s2C | 2C | C | % | 
| 2-thiouridine | s2U | 2U | U | 2 | 
| 2’-O-methyladenosine | Am | 0A | A | : | 
| 2’-O-methylcytidine | Cm | 0C | C | B | 
| 2’-O-methylguanosine | Gm | 0G | G | # | 
| 2’-O-methylinosine | Im | 09A | A | ≤ | 
| 2’-O-methylpseudouridine | Ym | 09U | U | Z | 
| 2’-O-methyluridine | Um | 0U | U | J | 
| 2’-O-methyluridine 5-oxyacetic acid methyl ester | mcmo5Um | 0503U | U | Ä | 
| 2’-O-ribosyladenosine (phosphate) | Ar(p) | 00A | A | ^ | 
| 2’-O-ribosylguanosine (phosphate) | Gr(p) | 00G | G | ℑ | 
| 3,2’-O-dimethyluridine | m3Um | 03U | U | σ | 
| 3-(3-amino-3-carboxypropyl)-5,6-dihydrouridine | acp3D | 308U | U | Ð | 
| 3-(3-amino-3-carboxypropyl)pseudouridine | acp3Y | 309U | U | Þ | 
| 3-(3-amino-3-carboxypropyl)uridine | acp3U | 30U | U | X | 
| 3-methylcytidine | m3C | 3C | C | ’ | 
| 3-methylpseudouridine | m3Y | 39U | U | κ | 
| 3-methyluridine | m3U | 3U | U | δ | 
| 4-demethylwyosine | imG-14 | 4G | G | † | 
| 4-thiouridine | s4U | 74U | U | 4 | 
| 5,2’-O-dimethylcytidine | m5Cm | 05C | C | τ | 
| 5,2’-O-dimethyluridine | m5Um | 05U | U | ¤ | 
| 5-(carboxyhydroxymethyl)-2’-O-methyluridine methyl ester | mchm5Um | 0522U | U | b | 
| 5-(carboxyhydroxymethyl)uridine methyl ester | mchm5U | 522U | U | , | 
| 5-(isopentenylaminomethyl)-2-thiouridine | inm5s2U | 2583U | U | ½ | 
| 5-(isopentenylaminomethyl)-2’-O-methyluridine | inm5Um | 0583U | U | ¼ | 
| 5-(isopentenylaminomethyl)uridine | inm5U | 583U | U | ¾ | 
| 5-aminomethyl-2-geranylthiouridine | nm5ges2U | 21510U | U | Δ | 
| 5-aminomethyl-2-selenouridine | nm5se2U | 20510U | U | π | 
| 5-aminomethyl-2-thiouridine | nm5s2U | 2510U | U | ∫ | 
| 5-aminomethyluridine | nm5U | 510U | U | ∪ | 
| 5-carbamoylhydroxymethyluridine | nchm5U | 531U | U | r | 
| 5-carbamoylmethyl-2-thiouridine | ncm5s2U | 253U | U | l | 
| 5-carbamoylmethyl-2’-O-methyluridine | ncm5Um | 053U | U | ~ | 
| 5-carbamoylmethyluridine | ncm5U | 53U | U | & | 
| 5-carboxyhydroxymethyluridine | chm5U | 520U | U | ≥ | 
| 5-carboxymethyl-2-thiouridine | cm5s2U | 2540U | U | ℘ | 
| 5-carboxymethylaminomethyl-2-geranylthiouridine | cmnm5ges2U | 2151U | U | f | 
| 5-carboxymethylaminomethyl-2-selenouridine | cmnm5se2U | 2051U | U | ⊥ | 
| 5-carboxymethylaminomethyl-2-thiouridine | cmnm5s2U | 251U | U | $ | 
| 5-carboxymethylaminomethyl-2’-O-methyluridine | cmnm5Um | 051U | U | ) | 
| 5-carboxymethylaminomethyluridine | cmnm5U | 51U | U | ! | 
| 5-carboxymethyluridine | cm5U | 52U | U | ◊ | 
| 5-cyanomethyluridine | cnm5U | 55U | U | Ѷ | 
| 5-formyl-2’-O-methylcytidine | f5Cm | 071C | C | ° | 
| 5-formylcytidine | f5C | 71C | C | × | 
| 5-hydroxycytidine | ho5C | 50C | C | Ç | 
| 5-hydroxymethylcytidine | hm5C | 51C | C | ∅ | 
| 5-hydroxyuridine | ho5U | 50U | U | ∝ | 
| 5-methoxycarbonylmethyl-2-thiouridine | mcm5s2U | 2521U | U | 3 | 
| 5-methoxycarbonylmethyl-2’-O-methyluridine | mcm5Um | 0521U | U | ∩ | 
| 5-methoxycarbonylmethyluridine | mcm5U | 521U | U | 1 | 
| 5-methoxyuridine | mo5U | 501U | U | 5 | 
| 5-methyl-2-thiouridine | m5s2U | 25U | U | F | 
| 5-methylaminomethyl-2-geranylthiouridine | mnm5ges2U | 21511U | U | h | 
| 5-methylaminomethyl-2-selenouridine | mnm5se2U | 20511U | U | ≅ | 
| 5-methylaminomethyl-2-thiouridine | mnm5s2U | 2511U | U | S | 
| 5-methylaminomethyluridine | mnm5U | 511U | U | { | 
| 5-methylcytidine | m5C | 5C | C | ? | 
| 5-methyldihydrouridine | m5D | 58U | U | ρ | 
| 5-methyluridine | m5U | 5U | U | T | 
| 5-taurinomethyl-2-thiouridine | tm5s2U | 254U | U | ∃ | 
| 5-taurinomethyluridine | tm5U | 54U | U | Ê | 
| 7-aminocarboxypropyl-demethylwyosine | yW-86 | 47G | G | ¥ | 
| 7-aminocarboxypropylwyosine | yW-72 | 347G | G | Ω | 
| 7-aminocarboxypropylwyosine methyl ester | yW-58 | 348G | G | ⇑ | 
| 7-aminomethyl-7-deazaguanosine | preQ1tRNA | 101G | G | ∉ | 
| 7-cyano-7-deazaguanosine | preQ0tRNA | 100G | G | φ | 
| 7-methylguanosine | m7G | 7G | G | 7 | 
| 8-methyladenosine | m8A | 8A | A | â | 
| N2,2’-O-dimethylguanosine | m2Gm | 02G | G | γ | 
| N2,7,2’-O-trimethylguanosine | m2,7Gm | 027G | G | æ | 
| N2,7-dimethylguanosine | m2,7G | 27G | G | ∨ | 
| N2,N2,2’-O-trimethylguanosine | m2,2Gm | 022G | G | | | 
| N2,N2,7-trimethylguanosine | m2,2,7G | 227G | G | ∠ | 
| N2,N2-dimethylguanosine | m2,2G | 22G | G | R | 
| N2-methylguanosine | m2G | 2G | G | L | 
| N4,2’-O-dimethylcytidine | m4Cm | 04C | C | λ | 
| N4,N4,2’-O-trimethylcytidine | m4,4Cm | 044C | C | β | 
| N4,N4-dimethylcytidine | m4,4C | 44C | C | μ | 
| N4-acetyl-2’-O-methylcytidine | ac4Cm | 042C | C | ℵ | 
| N4-acetylcytidine | ac4C | 42C | C | M | 
| N4-methylcytidine | m4C | 4C | C | ν | 
| N6,2’-O-dimethyladenosine | m6Am | 06A | A | χ | 
| N6,N6,2’-O-trimethyladenosine | m6,6Am | 066A | A | η | 
| N6,N6-dimethyladenosine | m6,6A | 66A | A | ζ | 
| N6-(cis-hydroxyisopentenyl)adenosine | io6A | 60A | A | ` | 
| N6-acetyladenosine | ac6A | 64A | A | ⇓ | 
| N6-formyladenosine | f6A | 67A | A | Ϩ | 
| N6-glycinylcarbamoyladenosine | g6A | 65A | A | ≡ | 
| N6-hydroxymethyladenosine | hm6A | 68A | A | Ϫ | 
| N6-hydroxynorvalylcarbamoyladenosine | hn6A | 63A | A | √ | 
| N6-isopentenyladenosine | i6A | 61A | A | Θ | 
| N6-methyl-N6-threonylcarbamoyladenosine | m6t6A | 662A | A | E | 
| N6-methyladenosine | m6A | 6A | A | = | 
| N6-threonylcarbamoyladenosine | t6A | 62A | A | 6 | 
| agmatidine | C+ | 20C | C | ¿ | 
| archaeosine | G+ | 103G | G | ( | 
| cyclic N6-threonylcarbamoyladenosine | ct6A | 69A | A | e | 
| dihydrouridine | D | 8U | U | D | 
| epoxyqueuosine | oQtRNA | 102G | G | ς | 
| galactosyl-queuosine | galQtRNA | 104G | G | 9 | 
| glutamyl-queuosine | gluQtRNA | 105G | G | ⊄ | 
| hydroxy-N6-threonylcarbamoyladenosine | ht6A | 2165A | A | « | 
| hydroxywybutosine | OHyW | 34830G | G | ⊆ | 
| inosine | I | 9A | A | I | 
| isowyosine | imG2 | 42G | G | ⊇ | 
| mannosyl-queuosine | manQtRNA | 106G | G | 8 | 
| methylated undermodified hydroxywybutosine | OHyWy | 3480G | G | y | 
| methylwyosine | mimG | 342G | G | ∑ | 
| peroxywybutosine | o2yW | 34832G | G | W | 
| pseudouridine | Y | 9U | U | P | 
| queuosine | QtRNA | 10G | G | Q | 
| undermodified hydroxywybutosine | OHyWx | 3470G | G | š | 
| unknown methylated base | Xm | 0X | N | Î | 
| unknown modification | xX | X | N | ÷ | 
| unknown modified adenosine | xA | ?A | A | H | 
| unknown modified cytidine | xC | ?C | C | < | 
| unknown modified guanosine | xG | ?G | G | ; | 
| unknown modified uridine | xU | ?U | U | Ü | 
| uridine 5-oxyacetic acid | cmo5U | 502U | U | V | 
| uridine 5-oxyacetic acid methyl ester | mcmo5U | 503U | U | υ | 
| wybutosine | yW | 3483G | G | Y | 
| wyosine | imG | 34G | G | € | 
sessionInfo()## R version 4.5.0 RC (2025-04-04 r88126)
## Platform: x86_64-pc-linux-gnu
## Running under: Ubuntu 24.04.2 LTS
## 
## Matrix products: default
## BLAS:   /home/biocbuild/bbs-3.21-bioc/R/lib/libRblas.so 
## LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.12.0  LAPACK version 3.12.0
## 
## locale:
##  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C              
##  [3] LC_TIME=en_GB              LC_COLLATE=C              
##  [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8   
##  [7] LC_PAPER=en_US.UTF-8       LC_NAME=C                 
##  [9] LC_ADDRESS=C               LC_TELEPHONE=C            
## [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       
## 
## time zone: America/New_York
## tzcode source: system (glibc)
## 
## attached base packages:
## [1] stats4    stats     graphics  grDevices utils     datasets  methods  
## [8] base     
## 
## other attached packages:
## [1] Modstrings_1.24.0   Biostrings_2.76.0   GenomeInfoDb_1.44.0
## [4] XVector_0.48.0      IRanges_2.42.0      S4Vectors_0.46.0   
## [7] BiocGenerics_0.54.0 generics_0.1.3      BiocStyle_2.36.0   
## 
## loaded via a namespace (and not attached):
##  [1] crayon_1.5.3            httr_1.4.7              cli_3.6.4              
##  [4] knitr_1.50              rlang_1.1.6             xfun_0.52              
##  [7] stringi_1.8.7           UCSC.utils_1.4.0        jsonlite_2.0.0         
## [10] glue_1.8.0              htmltools_0.5.8.1       sass_0.4.10            
## [13] rmarkdown_2.29          evaluate_1.0.3          jquerylib_0.1.4        
## [16] fastmap_1.2.0           yaml_2.3.10             lifecycle_1.0.4        
## [19] bookdown_0.43           stringr_1.5.1           BiocManager_1.30.25    
## [22] compiler_4.5.0          digest_0.6.37           R6_2.6.1               
## [25] GenomeInfoDbData_1.2.14 magrittr_2.0.3          GenomicRanges_1.60.0   
## [28] bslib_0.9.0             tools_4.5.0             cachem_1.1.0Boccaletto, Pietro, Magdalena A. Machnicka, Elzbieta Purta, Pawel Piatkowski, Blazej Baginski, Tomasz K. Wirecki, Valérie de Crécy-Lagard, et al. 2018. “MODOMICS: A Database of Rna Modification Pathways. 2017 Update.” Nucleic Acids Research 46 (D1): D303–D307. https://doi.org/10.1093/nar/gkx1030.