Table 1.

Inventory of rRNA modifications in yeast. The rRNA, position (Posn.) and type (Mod.) of the modification and the enzyme/snoRNP(s) that introduce it are given, with information on whether partial modification was observed (✓; <85%)²¹ or not (x), and whether modification occurs early/chromatin-associated (E),¹⁸ in late nucleolar/nuclear (LN) particles or in the cytoplasm (C). A lack of information on the timing is indicated by “–.” Enzymes/snoRNPs targeting the same position sequentially are separated by “,” and alternative enzymes/snoRNPs that can install a single modification at a given site are separated by “/”. The information presented in this table is compiled from various references cited in the text.

rRNA	Posn.	Mod.	Enzyme/snoRNP	Partial	Timing	rRNA	Posn.	Mod.	Enzyme/snoRNP	Partial	Timing
18S	28	Am	snR74	x	E	18S	1415	Ψ	snR83	✓	—
18S	100	Am	snR51	✓	LN	18S	1428	Gm	snR56	x	E
18S	106	Ψ	snR44	x	—	18S	1572	Gm	snR57	x	E
18S	120	Ψ	snR49	x	—	18S	1575	m7G	Bud23	x	—
18S	211	Ψ	snR49	✓	—	18S	1639	Cm	snR70	✓	E
18S	302	Ψ	snR49	x	—	18S	1773	ac4C	Kre33	x	—
18S	414	Cm	U14	x	E	18S	1781	m26A	Dim1	x	C
18S	420	Am	snR52	x	E	18S	1782	m26A	Dim1	x	C
18S	436	Am	snR87	✓	E	5.8S	73	Ψ	snR43	✓	—
18S	466	Ψ	snR189	✓	—	25S	645	m1A	Rrp8 (Bmt1)	x	—
18S	541	Am	snR41	x	E	25S	649	Am	U18	x	E
18S	562	Gm	?	✓	E	25S	650	Cm	U18	x	E
18S	578	Um	snR77	x	E	25S	663	Cm	snR58	✓	E
18S	619	Am	snR47	x	E	25S	776	Ψ	snR80	x	—
18S	632	Ψ	snR161	✓	—	25S	805	Gm	snR39b	x	E
18S	759	Ψ	snR80	x	—	25S	807	Am	snR39/snR59	x	E
18S	766	Ψ	snR161	x	—	25S	817	Am	snR60	x	LN
18S	796	Am	snR53	x	E	25S	867	Gm	snR50	✓	LN
18S	974	Am	snR54	x	E	25S	876	Am	snR72	✓	LN
18S	999	Ψ	snR31	✓	—	25S	898	Um	snR40	x	LN
18S	1007	Cm	snR79	x	E	25S	908	Gm	snR60	x	E
18S	1126	Gm	snR41	x	E	25S	956	m3U	Bmt5	x	—
18S	1181	Ψ	snR85	x	—	25S	960	Ψ	snR8	x	—
18S	1187	Ψ	snR36	x	—	25S	966	Ψ	snR43	x	—
18S	1191	m1acp3Ψ	snR35,Emg1,Tsr3	x	E,LN,C	25S	986	Ψ	snR8	x	—
18S	1269	Um	snR55	x	E	25S	990	Ψ	snR49	x	—
18S	1271	Gm	snR40	x	E	25S	1004	Ψ	snR5	✓	—
18S	1280	ac4C	Kre33	✓	—	25S	1042	Ψ	snR33	x	—
18S	1290	Ψ	snR83	x	—	25S	1052	Ψ	snR81	x	—
25S	1056	Ψ	snR44	x	—	25S	2351	Ψ	snR82	x	—
25S	1110	Ψ	snR82	✓	—	25S	2416	Ψ	snR11	x	—
25S	1124	Ψ	snR5	x	—	25S	2417	Um	snR66	x	E
25S	1133	Am	snR61	x	E	25S	2421	Um	snR78	x	LN
25S	1437	Cm	U24	x	E	25S	2619	Gm	snR67	x	E
25S	1449	Am	U24	x	E	25S	2634	m3U	Bmt5	x	—
25S	1450	Gm	U24	x	E	25S	2640	Am	snR68	x	LN
25S	1888	Um	snR62	x	—	25S	2724	Um	snR67	x	E
25S	2129	Ψ	snR3	x	—	25S	2729	Um	snR51	✓	E
25S	2133	Ψ	snR3	x	—	25S	2735	Ψ	snR189	x	—
25S	2142	m1A	Bmt2	x	—	25S	2791	Gm	snR48	x	E
25S	2191	Ψ	snR32	x	—	25S	2793	Gm	snR48	x	E
25S	2197	Cm	snR76	x	E	25S	2815	Gm	snR38	x	E
25S	2220	Am	snR47	x	E	25S	2826	Ψ	snR34	x	—
25S	2256	Am	snR63	x	LN	25S	2843	m3U	Bmt6	x	—
25S	2258	Ψ	snR191	x	—	25S	2865	Ψ	snR46	x	—
25S	2260	Ψ	snR191	x	—	25S	2870	m5C	Nop2 (Bmt4)	x	—
25S	2264	Ψ	snR3	x	—	25S	2880	Ψ	snR34	x	—
25S	2266	Ψ	snR84	x	—	25S	2921	Um	snR52/Sbp1	x	E
25S	2278	m5C	Rcm1 (Bmt3)	x	—	25S	2922	Gm	Sbp1	x	LN
25S	2280	Am	snR13	x	E	25S	2923	Ψ	snR10	x	—
25S	2281	Am	snR13	x	E	25S	2944	Ψ	snR37	✓	—
25S	2288	Gm	snR75	x	E	25S	2946	Am	snR71	x	E
25S	2314	Ψ	snR86	x	—	25S	2948	Cm	snR69	x	E
25S	2337	Cm	snR64	x	—	25S	2959	Cm	snR73	x	E
25S	2340	Ψ	snR9	x	—	25S	2975	Ψ	snR42	x	—
25S	2347	Um/Ψ/Ψm	snR65,snR9	x	—	5S	50	Ψ	Pus7	x	—
25S	2349	Ψ	snR82	x	—