TABLE 2.

Modifications at known nucleotide positions in tRNAs

tRNA position	Modification(s)
1	Ψ
4	Am, Cm
8	s4U
9	m1A, m1G, s4U
10	m2G, m2,2G, m2Gm, m2,2Gm
12	ac4C
13	Ψ
15	G+, preQ0
16	D
17	D, Gm
19	D
20	D, acp3U
21	Ψ
26	m2G, m2,2G, m2Gm, m2,2Gm
27	Ψ
28	Ψ
31	Ψ
32	Ψ, m3C, Cm, s2C, s2U, ms2C
33	s2U
34	Ψ, cnm5U, ho5U, mo5U, cmo5U, mcmo5U, mcmo5Um, m3U, I, f5C, m5C, m3C, preQ0, preQ1, Q, oQ, galQ, manQ, gluQ, Cm, s2U, s2Um, nm5s2U, mnm5s2U, cmnm5s2U, C+, k2C, ac4C, Gm, mcm5U, mcm5Um, ncm5U, ncm5Um, τm5U, τm5s2U, cmnm5U, cmnm5s2U, mnm5se2U, cmnm5ges2U, mnm5ges2U, cmnm5se2U, mnm5se2U, mnm5U, nm5U, nchm5U, se2U, ges2U, chm5U, mchm5U, mcm5s2U, ncm5s2U, cm5s2U
35	Ψ
36	Ψ
37	i6A, io6A, ms2i6A, ms2io6A, t6A, g6A, ht6A, m6t6A, ct6A, ms2t6A, ms2ct6A, I, m1A, m1I, m2A, m1G, imG‐14, imG, imG2, mimG, yW‐86, yW‐72, yW‐58, yW, OHyW*, OHyWy, o2yW, OHyW, m6A, s2C
38	Ψ
39	Ψ, Um
40	m5C
46	m7G
47	acp3U
48	m5C
49	m5C
52	Ψ
53	Ψ
54	Ψ,m1Ψ, m5U, m5s2U
55	Ψ
56	Cm
57	m1A, m1I, I
58	m1A, m1I
64	Ar(p), Gr(p)
65	Ψ
66	Ψ
Unknown location	msms2i6A, ac6A, hn6A, ms2hn6A, m6,6A, acp3D, m3Ψ, m4,4Cm, m6Am, m6,6Am, m1Am, Im, m1Im, m1Gm, m2,7Gm, m4Cm, m5Cm, f5Cm, ac4Cm, mchm5Um, mcmo5Um, inm5Um

Note: Specific positions within tRNAs, labeled “tRNA position,” indicate which nucleotide is modified (related to Figure 4). The column labeled “Modification(s)” indicates which modification(s) can be found at a given nucleotide position. All modifications are abbreviated as indicated in “Symbol” column of Table 1.