Modification reactions

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Name Reaction type level 1 Reaction type level 2 Reaction type level 3
Input group Output group Introduced group name Introduced group type
Atom address Site Modification level

Name Reaction type level 1 Reaction type level 2 Reaction type level 3 Input group Output group Introduced group name Introduced group type Atom address Site Modification level
(pN):m(pN) methylation alkylation group addition none *C methyl hydrocarbon O5'.O2A phosphate 2
(pN):pG(pN) 5ʹ-3ʹ guanylylation nucleotide addition group addition OH [O-]P(=O)(O)OC[C@@H]3O[C@H](n2cnc1c2N=C(N)NC1=O)[C@@H](O)[C@H]3O* guanylyl nucleotide O5'.P3 phosphate 0
A:Am methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 1
A:Ar(p) phosphoribosylation acylation group addition H O[C@@H]1[C@H](OP(=O)(O)O)O[C@H](*)[C@H]1O phosphoribosyl phosphoribose 2′O sugar 1
A:I deamination NH2/O exchange group exchange NH2 *=O oxo oxo C6 base/endocyclic 1
A:g6A carbamoylation acylation group addition H *C(=O)NCC(=O)O glycylcarbamoyl acyl N6 base/exocyclic 1
A:hn6A carbamoylation acylation group addition H *C(=O)NC(C(O)=O)C(O)CC hydroxynorvalylcarbamoyl acyl N6 base/exocyclic 1
A:i6A isopentenylation alkylation group addition H *CC=C(C)/C isopenthenyl hydrocarbon N6 base/exocyclic 1
A:m1A methylation alkylation group addition none *C methyl hydrocarbon N1 base/endocyclic 1
A:m2A methylation alkylation group addition none *C methyl hydrocarbon C2 base/endocyclic 1
A:m6A methylation alkylation group addition H *C methyl hydrocarbon N6 base/exocyclic 1
A:m8A methylation alkylation group addition none *C methyl hydrocarbon C8 base/endocyclic 1
A:t6A carbamoylation acylation group addition H *C(=O)NC(C(O)=O)C(O)C threonylcarbamoyl acyl N6 base/exocyclic 1
Am:Im deamination NH2/O exchange group exchange NH2 *=O oxo oxo C6 base/endocyclic 2
Am:m1Am methylation alkylation group addition none *C methyl hydrocarbon N1 base/endocyclic 2
Am:m6Am methylation alkylation group addition H *C methyl hydrocarbon N6 base/exocyclic 2
C:C+ agmatinylation amination group addition O *NCCCCCCNC(=N)N agmatinyl polyamine C2 base/endocyclic 1
C:Cm methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 1
C:U deamination NH2/O exchange group exchange NH2 *=O oxo oxo C4 base/endocyclic 0
C:ac4C acetylation acylation group addition H *C(=O)C acetyl acyl N4 base/exocyclic 1
C:f5C formylation acylation group addition H *C([H])=O formyl acyl C5 base/endocyclic 1
C:hm5C hydroxymethylation hydroxymethylation group addition H *CO hydroxymethyl hydroxyalkyl C5 base/endocyclic 1
C:ho5C hydroxylation oxygen addition group addition H *O hydroxyl hydroxyl C5 base/endocyclic 1
C:k2C lysylation amination group addition O *NCCCCC(N)C(O)=O lysyl amino acid C2 base/endocyclic 1
C:m3C methylation alkylation group addition none *C methyl hydrocarbon N3 base/endocyclic 1
C:m4C methylation alkylation group addition H *C methyl hydrocarbon N4 base/exocyclic 1
C:m5C methylation alkylation group addition H *C methyl hydrocarbon C5 base/endocyclic 1
C:s2C O/S exchange O/S exchange group exchange O *=S thio sulphur C2 base/endocyclic 1
Cm:ac4Cm acetylation acylation group addition H *C(=O)C acetyl acyl N4 base/exocyclic 2
Cm:f5Cm formylation acylation group addition H *C([H])=O formyl acyl C5 base/endocyclic 2
Cm:m4Cm methylation alkylation group addition H *C methyl hydrocarbon N4 base/exocyclic 2
Cm:m5Cm methylation alkylation group addition H *C methyl hydrocarbon C5 base/endocyclic 2
CoA(pN):acCoA(pN) acetylation acylation group addition H *C(=O)C acetyl acyl O5'.P3 extra group 2
CoA(pN):malonyl-CoA(pN) carboxylation acylation group addition H *C(=O)CC(=O)O malonyl acyl O5'.P3 extra group 2
CoA(pN):succinyl-CoA(pN) carboxylation acylation group addition H *C(=O)CCC(=O)O succinyl acyl O5'.P3 extra group 2
D:acp3D 3-amino-3-carboxypropylation acylation group addition H *CCC(N)C(=O)O 3-amino-3-carboxypropyl amino acid N3 base/endocyclic 2
D:m5D methylation alkylation group addition H *C methyl hydrocarbon C5 base/endocyclic 2
G:Gm methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 1
G:Gr(p) phosphoribosylation acylation group addition H O[C@@H]1[C@H](OP(=O)(O)O)O[C@H](*)[C@H]1O phosphoribosyl phosphoribose 2′O sugar 1
G:m1G methylation alkylation group addition H *C methyl hydrocarbon N1 base/endocyclic 1
G:m2G methylation alkylation group addition H *C methyl hydrocarbon N2 base/exocyclic 1
G:m7G methylation alkylation group addition none *C methyl hydrocarbon N7 base/endocyclic 1
Gm:m1Gm methylation alkylation group addition H *C methyl hydrocarbon N1 base/endocyclic 2
Gm:m2Gm methylation alkylation group addition H *C methyl hydrocarbon N2 base/exocyclic 2
Gpp(pN):m7Gpp(pN) methylation alkylation group addition none *C methyl hydrocarbon N7 base/endocyclic 3
I:Im methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 2
I:m1I methylation alkylation group addition H *C methyl hydrocarbon N1 base/endocyclic 2
Im:m1Im methylation alkylation group addition H *C methyl hydrocarbon N1 base/endocyclic 3
OHyW:o2yW O-peroxidaton oxygen addition group addition H *O* peroxide peroxide N1.O4 extra group 7
OHyWx:OHyWy methylation alkylation group addition H *C methyl hydrocarbon N1.O6 extra group 6
OHyWy:OHyW methoxycarbonylation acylation group addition H *C(=O)OC, *C methoxycarbonyl methoxycarbonyl N1.N5 extra group 7
Qbase:QtRNA transglycosylation base exchange group exchange NC2=Nc1ncnc1C(=O)N2 C1=CC(C(C1NCC2=CN(C3=C2C(=O)N=C(N3)N)C4C(C(C(O4)CO)O)O)O)O Qbase nucleobase C1ʹ sugar 0
QtRNA:Qbase N-glycosyl bond hydrolysis hydrolysis group removal C1=CC(C(C1NCC2=CN(C3=C2C(=O)N=C(N3)N)C4C(C(C(O4)CO)O)O)O)O *O hydroxyl hydroxyl C1ʹ sugar 0
QtRNA:galQtRNA galactosylation glycosylation group addition H O[C@@H]1[C@@H](O)[C@@H](O)[C@@H](CO)O[C@@]1(O)* galactosyl saccharide C7.O5 extra group 3
QtRNA:gluQtRNA glutamylation acylation group addition H *OC(=O)C(N)CCC(=O)O glutamyl amino acid C7.O5 base/exocyclic 3
QtRNA:manQtRNA mannosylation glycosylation group addition H OC1[C@H](O)[C@H](O)C(CO)O[C@]1(*)[H] mannosyl saccharide C7.O5 extra group 3
U:D hydrogenation hydrogenation group addition none *H, *H hydrogen hydrogen C5,C6 base/endocyclic 1
U:Um methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 1
U:Y pseudouridine formation isomerization isomerization none none none none N1, C5 base/endocyclic 1
U:acp3U 3-amino-3-carboxypropylation acylation group addition H *CCC(N)C(=O)O 3-amino-3-carboxypropyl amino acid N3 base/endocyclic 1
U:cm5U carboxymethylation alkylation group addition H *CC(=O)O carboxymethyl carboxymethyl C5 base/endocyclic 1
U:cmnm5U carboxymethylaminomethylation aminoalkylation group addition H *CNCC(=O)O carboxymethylaminomethyl aminoalkyl C5 base/endocyclic 1
U:ho5U hydroxylation oxygen addition group addition H *O hydroxyl hydroxyl C5 base/endocyclic 1
U:m3U methylation alkylation group addition H *C methyl hydrocarbon N3 base/endocyclic 1
U:m5U methylation alkylation group addition H *C methyl hydrocarbon C5 base/endocyclic 1
U:ncm5U carbamoylmethylation alkylation group addition H *CC(=O)N carbamoylmethyl acyl C5 base/endocyclic 1
U:nm5U aminomethylation aminoalkylation group addition H *CN aminomethyl aminoalkyl C5 base/endocyclic 2
U:s2U O/S exchange O/S exchange group exchange O *=S thio sulphur C2 base/endocyclic 1
U:s4U O/S exchange O/S exchange group exchange O *=S thio sulphur C4 base/endocyclic 1
U:tm5U taurinomethylation aminoalkylation group addition H *CNCCS(=O)(O)=O taurinomethyl aminoalkyl C5 base/endocyclic 1
Um:cmnm5Um carboxymethylaminomethylation aminoalkylation group addition H *CNCC(=O)O carboxymethylaminomethyl aminoalkyl C5 base/endocyclic 2
Um:s2Um O/S exchange O/S exchange group exchange O *=S thio sulphur C2 base/endocyclic 2
Y:Ym methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 2
Y:acp3Y 3-amino-3-carboxypropylation acylation group addition H *CCC(N)C(=O)O 3-amino-3-carboxypropyl amino acid N3 base/endocyclic 2
Y:m1Y methylation alkylation group addition H *C methyl hydrocarbon N1 base/endocyclic 2
Y:m3Y methylation alkylation group addition H *C methyl hydrocarbon N3 base/endocyclic 2
ac4C:ac4Cm methylation alkylation group addition H *C methyl hydrocarbon 2'O sugar 2
acp3U:acp3Y pseudouridine formation isomerization isomerization none none none none N1, C5 base/endocyclic 2
chm5U:mchm5U methylation alkylation group addition H *C methyl hydrocarbon C5.O3 extra group 3
cm5U:chm5U hydroxylation oxygen addition group addition H *O hydroxyl hydroxyl C5.C1 extra group 2
cm5U:mcm5U methylation alkylation group addition H *C methyl hydrocarbon C5.O3 extra group 2
cmnm5U:cmnm5Um methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 2
cmnm5U:cmnm5s2U O/S exchange O/S exchange group exchange O *=S thio sulphur C2 base/endocyclic 2
cmnm5U:nm5U decarboxymethylation dealkylation group removal *C(=O)O *[H] hydrogen hydrogen C5.N2 extra group 2
cmnm5ges2U:nm5ges2U decarboxymethylation dealkylation group removal *C(=O)O *[H] hydrogen hydrogen C5.N2 extra group 4
cmnm5s2U:cmnm5ges2U geranylation alkylation group addition none C\C(C)=C\CCC(\C)=C\C* geranyl hydrocarbon C2.S1 extra group 3
cmnm5s2U:cmnm5se2U S/Se exchange S/Se exchange group exchange S *[Se] seleno seleno C2 base/endocyclic 3
cmnm5s2U:nm5s2U decarboxymethylation dealkylation group removal *C(=O)O *[H] hydrogen hydrogen C5.N2 extra group 3
cmnm5se2U:nm5se2U decarboxymethylation dealkylation group removal *C(=O)O *[H] hydrogen hydrogen C5.N2 extra group 4
cmo5U:mcmo5U methylation alkylation group addition H *C methyl hydrocarbon C5.O4 extra group 4
ct6A:t6A hydration hydration group addition none O water molecule other N6.O2, N6.C4 extra group 1
f5C:f5Cm methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 2
ges2U:cmnm5ges2U carboxymethylaminomethylation aminoalkylation group addition H *CNCC(=O)O carboxymethylaminomethyl aminoalkyl C5 base/endocyclic 3
ges2U:nm5ges2U aminomethylation aminoalkylation group addition H *CN aminomethyl aminoalkyl C5 base/endocyclic 4
hm6A:f6A dehydrogenation dehydrogenation group removal H, H none none none N6.C1, N6.O2 extra group 3
hn6A:ms2hn6A methylthiolation thioalkylation group addition H *SC methylthio thioalkyl C2 base/endocyclic 2
ho5U:cmo5U carboxymethylation alkylation group addition H *CC(=O)O carboxymethyl carboxymethyl C5.O1 extra group 3
ho5U:mo5U methylation alkylation group addition H *C methyl hydrocarbon C5.O1 extra group 2
i6A:io6A hydroxylation oxygen addition group addition H *O hydroxyl hydroxyl C4.C5 extra group 2
i6A:ms2i6A methylthiolation thioalkylation group addition H *SC methylthio thioalkyl C2 base/endocyclic 2
imG-14:imG methylation alkylation group addition H *C methyl hydrocarbon N3 base/endocyclic 3
imG-14:imG2 methylation alkylation group addition H *C methyl hydrocarbon N1.C1 extra group 3
imG-14:yW-86 3-amino-3-carboxypropylation acylation group addition H *CCC(N)C(=O)O 3-amino-3-carboxypropyl amino acid N1.C1 extra group 3
imG2:mimG methylation alkylation group addition H *C methyl hydrocarbon N3 base/endocyclic 4
inm5U:inm5Um methylation alkylation group addition H *C methyl hydrocarbon 2'O sugar 4
io6A:ms2io6A methylthiolation thioalkylation group addition H *SC methylthio thioalkyl C2 base/endocyclic 3
m(pN):mm(pN) methylation alkylation group addition H *C methyl hydrocarbon O5'.O3A phosphate 3
m1A:m1Am methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 2
m1A:m1I deamination NH2/O exchange group exchange NH2 *=O oxo oxo C6 base/endocyclic 2
m1G:imG-14 acetylation condensation-cyclization group addition H,H2 *=C(C)* anhydro-acetic acid hydrocarbon N1.C1, N2 2
m1G:m1Gm methylation alkylation group addition H *C methyl hydrocarbon 2'O sugar 2
m1I:m1Im methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 3
m1Y:m1acp3Y 3-amino-3-carboxypropylation acylation group addition H *CCC(N)C(=O)O 3-amino-3-carboxypropyl amino acid N3 base/endocyclic 3
m2,2G:m2,2Gm methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 3
m2,7G:m2,2,7G methylation alkylation group addition H *C methyl hydrocarbon N2 base/exocyclic 3
m2,7G:m2,7Gm methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 3
m2,7Gpp(pN):m2,2,7Gpp(pN) methylation alkylation group addition H *C methyl hydrocarbon N2 base/exocyclic 5
m2A:m2,8A methylation alkylation group addition none *C methyl hydrocarbon C8 base/endocyclic 2
m2G:m2,2G methylation alkylation group addition H *C methyl hydrocarbon N2 base/exocyclic 2
m2G:m2Gm methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 2
m2Gm:m2,2Gm methylation alkylation group addition H *C methyl hydrocarbon N2 base/exocyclic 3
m2Gm:m2,7Gm methylation alkylation group addition none *C methyl hydrocarbon N7 base/endocyclic 3
m3U:m3Um methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 2
m4,4C:m4,4Cm methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 3
m4C:m4,4C methylation alkylation group addition H *C methyl hydrocarbon N4 base/exocyclic 2
m4C:m4Cm methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 2
m4Cm:m4,4Cm methylation alkylation group addition H *C methyl hydrocarbon N4 base/exocyclic 3
m5C:m5Cm methylation alkylation group addition H *C methyl hydrocarbon 2'O sugar 2
m5U:m5Um methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 2
m5U:m5s2U O/S exchange O/S exchange group exchange O *=S thio sulphur C2 base/endocyclic 2
m6,6A:m6,6Am methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 3
m6A:A demethylation dealkylation group removal *C *H hydrogen hydrogen N6 base/exocyclic 0
m6A:hm6A hydroxylation oxygen addition group addition H *O hydroxyl hydroxyl N6.C1 extra group 2
m6A:m6,6A methylation alkylation group addition H *C methyl hydrocarbon N6 base/exocyclic 2
m6A:m6Am methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 2
m6A:ms2m6A methylthiolation thioalkylation group addition H *SC methylthio thioalkyl C2 base/endocyclic 2
m6Am:m6,6Am methylation alkylation group addition H *C methyl hydrocarbon N6 base/exocyclic 3
m7G:m2,7G methylation alkylation group addition H *C methyl hydrocarbon N2 base/exocyclic 2
m7Gpp(pN):m2,7Gpp(pN) methylation alkylation group addition H *C methyl hydrocarbon N2 base/exocyclic 4
m8A:m2,8A methylation alkylation group addition none *C methyl hydrocarbon C2 base/endocyclic 2
mchm5U:mchm5Um methylation alkylation group addition H *C methyl hydrocarbon 2'O sugar 4
mcm5U:mchm5U hydroxylation oxygen addition group addition H *O hydroxyl hydroxyl C5.C1 extra group 3
mcm5U:mcm5Um methylation alkylation group addition H *C methyl hydrocarbon 2'O sugar 3
mcm5U:mcm5s2U O/S exchange O/S exchange group exchange O *=S thio sulphur C2 base/endocyclic 3
mcm5Um:mchm5Um hydroxylation oxygen addition group addition H *O hydroxyl hydroxyl C5.C1 extra group 4
mnm5U:mnm5s2U O/S exchange O/S exchange group exchange O *=S thio sulphur C2 base/endocyclic 4
mnm5s2U:mnm5ges2U geranylation alkylation group addition none C\C(C)=C\CCC(\C)=C\C* geranyl hydrocarbon C2.S1 extra group 5
mnm5s2U:mnm5se2U S/Se exchange S/Se exchange group exchange S *[Se] seleno seleno C2 base/endocyclic 5
ms2i6A:ms2io6A hydroxylation oxygen addition group addition H *O hydroxyl hydroxyl C4.C5 extra group 3
ncm5U:nchm5U hydroxylation oxygen addition group addition H *O hydroxyl hydroxyl C5.C1 extra group 2
ncm5U:ncm5Um methylation alkylation group addition H *C methyl hydrocarbon 2′O sugar 2
ncm5U:ncm5s2U O/S exchange O/S exchange group exchange O *=S thio sulphur C2 base/endocyclic 2
nm5U:inm5U isopentenylation alkylation group addition H *CC=C(C)/C isopenthenyl hydrocarbon C5.N2 base/exocyclic 3
nm5U:mnm5U methylation alkylation group addition H *C methyl hydrocarbon C5.N2 extra group 3
nm5U:nm5s2U O/S exchange O/S exchange group exchange O *=S thio sulphur C2 base/endocyclic 3
nm5ges2U:mnm5ges2U methylation alkylation group addition H *C methyl hydrocarbon C5.N2 extra group 5
nm5s2U:inm5s2U isopentenylation alkylation group addition H *CC=C(C)/C isopenthenyl hydrocarbon C5.N2 base/exocyclic 4
nm5s2U:mnm5s2U methylation alkylation group addition H *C methyl hydrocarbon C5.N2 extra group 4
nm5s2U:nm5ges2U geranylation alkylation group addition none C\C(C)=C\CCC(\C)=C\C* geranyl hydrocarbon C2.S1 extra group 4
nm5s2U:nm5se2U S/Se exchange S/Se exchange group exchange S *[Se] seleno seleno C2 base/endocyclic 4
nm5se2U:mnm5se2U methylation alkylation group addition H *C methyl hydrocarbon C5.N2 extra group 5
oQtRNA:QtRNA epoxide deoxygenation deoxygenation group removal O none none none C7.C4,C7.C6 extra group 2
p(pN):Gpp(pN) 5ʹ-5ʹ guanylylation nucleotide addition group addition *P(=O)(O)OP(=O)(O)O [O-]P(=O)(O)OC[C@@H]3O[C@H](n2cnc1c2N=C(N)NC1=O)[C@@H](O)[C@H]3O* guanylyl nucleotide O5'.P3 phosphate 0
pp(pN):(pN) excision from a larger primary transcript hydrolysis group removal *P(=O)(O)OP(=O)(O)O *[H] hydrogen hydrogen O5'.O3A phosphate 0
pp(pN):CoA(pN) group addition group addition group addition *P(=O)(O)OP(=O)(O)O SCCNC(=O)CCNC(=O)C(O)C(C)(C)COP([O-])(=O)OP([O-])(=O)OC[C@H]3O[C@@H](n2cnc1c(N)ncnc12)C(O)[C@H]3O* dephospho-coenzyme A other group O5'.P3 phosphate 1
pp(pN):NAD(pN) nicotinamide adenine dinucleotidylation nucleotide addition group addition *P(=O)(O)OP(=O)(O)O NC(=O)c1ccc[n+](c1)C5OC(COP([O-])(=O)OP([O-])(=O)OC[C@H]4O[C@@H](n3cnc2c(N)ncnc23)C(O)[C@H]4O*)C(O)C5O nicotinamide adenine dinucleotide nucleotide O5'.P3 phosphate 1
pp(pN):mpp(pN) methylation alkylation group addition none *C methyl hydrocarbon O5'.O2G phosphate 1
pp(pN):p(pN) dephosphorylation hydrolysis group removal *P(O)(O)=O *[H] hydrogen hydrogen O5'.O3B phosphate 1
preQ0base:preQ0tRNA transglycosylation base exchange group exchange NC2=Nc1ncnc1C(=O)N2 NC2=Nc1n(*)cc(C#N)c1C(=O)N2 preQ0 base nucleobase C1ʹ sugar 0
preQ0base:preQ1base hydrogenation hydrogenation group addition none *H hydrogen hydrogen C7.N2 extra group -1
preQ0tRNA:G+ amination amination group addition none *N, *[H] ammonia ammonia C7.C1, C7.N2 extra group 1
preQ1base:preQ1tRNA transglycosylation base exchange group exchange NC2=Nc1ncnc1C(=O)N2 NC2=Nc1ncc(CN)c1C(=O)N2 preQ1 base nucleobase C1ʹ sugar 0
preQ1tRNA:oQtRNA 2,3-epoxy-4,5-dihydroxycyclopentanylation alkylation group addition H *C2C1OC1C(O)C2O 2,3-epoxy-4,5-dihydroxycyclopentane group epoxycyclopentane group C7.N2 extra group 1
s2U:cmnm5s2U carboxymethylaminomethylation aminoalkylation group addition H *CNCC(=O)O carboxymethylaminomethyl aminoalkyl C5 base/endocyclic 2
s2U:ges2U geranylation alkylation group addition none C\C(C)=C\CCC(\C)=C\C* geranyl hydrocarbon C2.S1 extra group 2
s2U:nm5s2U aminomethylation aminoalkylation group addition H *CN aminomethyl aminoalkyl C5 base/endocyclic 3
s2U:s2Um methylation alkylation group addition H *C methyl hydrocarbon 2'O sugar 2
s2U:se2U S/Se exchange S/Se exchange group exchange S *[Se] seleno seleno C2 base/endocyclic 2
s2U:tm5s2U taurinomethylation aminoalkylation group addition H *CNCCS(=O)(O)=O taurinomethyl aminoalkyl C5 base/endocyclic 2
se2U:cmnm5se2U carboxymethylaminomethylation aminoalkylation group addition H *CNCC(=O)O carboxymethylaminomethyl aminoalkyl C5 base/endocyclic 3
se2U:nm5se2U aminomethylation aminoalkylation group addition H *CN aminomethyl aminoalkyl C5 base/endocyclic 4
t6A:ct6A dehydration dehydration group removal H, *O none none none N6.O2, N6.C4 extra group 2
t6A:m6t6A methylation alkylation group addition H *C methyl hydrocarbon N6 base/exocyclic 2
t6A:ms2t6A methylthiolation thioalkylation group addition H *SC methylthio thioalkyl C2 base/endocyclic 2
tm5U:tm5s2U O/S exchange O/S exchange group exchange O *=S thio sulphur C2 base/endocyclic 2
xX:Xm methylation alkylation group addition H *C methyl hydrocarbon 2ʹO sugar None
yW-58:yW methoxycarbonylation acylation group addition H *C(=O)OC methoxycarbonyl methoxycarbonyl N1.N5 extra group 6
yW-72:OHyWx hydroxylation oxygen addition group addition H *O hydroxyl hydroxyl N1.C3 extra group 5
yW-72:yW-58 methylation alkylation group addition H *C methyl hydrocarbon N1.C6 extra group 5
yW-86:yW-72 methylation alkylation group addition H *C methyl hydrocarbon N3 base/endocyclic 4