Table 4. Quantification of H-bond strengths from LR-HNCO nuclear magnetic resonance (NMR) experiments for all Kyrpides, Ouzounis, Woese (KOW) domains.

		EcNusG-KOW				MtNusG-KOW				MjSpt5-KOW
H-bond #	β-Sheet	Donor	Acceptor	|h3JNC’| (Hz)	σ |h3JNC’| (Hz)	Donor	Acceptor	|h3JNC’| (Hz)	σ |h3JNC’| (Hz)	Donor	Acceptor	|h3JNC’| (Hz)	σ |h3JNC’| (Hz)
1	β1-β2	131	148	0.69	0.0077	188	205	0.61	0.0098	92	109	0.70	0.013
2	β1-β2	148	132	0.72	0.0083	205	189	0.69	0.0094	109	93	0.79	0.0088
3	β1-β2	134	146	0.67	0.0081	191	203	0.56	0.011	95	107	0.77	0.012
4	β1-β2	146	134	0.62	0.0096	203	191	0.62	0.0094	107	95	0.67	0.0095
5	β1-β2	136	144	0.65	0.0073	193	201	0.65	0.0080	97	105	0.68	0.048
6	β1-β2	143	136	0.65	0.0088	200	193	0.76	0.013	104	97	0.82	0.012
7	β2-β3	147	161	0.37	0.0105	204	218	0.31	0.015	108	122	0.54	0.010
8	β2-β3	161	147	Peak overlap		218	204	0.69	0.011	122	108	0.65	0.010
9	β2-β3	149	159	0.67	0.012	206	216	0.53	0.013	110	120	0.57	0.030
10	β2-β3	159	150	0.50	0.0086	216	207	0.45	0.012	120	111	0.60	0.010
11	β2-β3	152	157	0.46	0.019	209	214	Peak overlap		113	118	–	–
12	β3-β4	158	173	0.78	0.0077	215	230	0.83	0.0088	119	134	No HNCO peak
13	β3-β4	173	158	0.64	0.010	230	215	0.62	0.011	134	119	0.62	0.010
14	β3-β4	160	171	0.73	0.0056	217	228	0.75	0.0089	121	132	0.88	0.012
15	β3-β4	171	161	Peak overlap		228	217	0.73	0.0062	132	121	0.47	0.014
16	β3-β4	162	169	0.51	0.0074	219	226	0.50	0.0090	123	130	No H-bond distance
17	β3-β4	169	162	0.60	0.0066	226	219	0.61	0.0091	No equivalent		–	–
18	β3-β4	167	164	–	–	224	221	0.20	0.019	No equivalent		–	–
19	β5-β1	137	177	0.46	0.017	194	234	0.52	0.025	98	138	No HNCO peak
20	β5-β1	179	135	Peak overlap		236	192	0.47	0.016	140	96	Peak overlap
21	β5-β1	135	179	0.73	0.0060	192	236	Peak overlap		96	140	Peak overlap
22	β5-β1	181	133	–	–	238	190	–	–	142	94	0.46	0.023
23	β5-β1	No equivalent		–	–	No equivalent		–	–	143	94	0.27	0.022
24	β5-β1	No equivalent		–	–	No equivalent		–	–	94	143	0.57	0.010
		hSpt5-KOW5				EcRfaH-KOW				VcRfaH-KOW
H-bond #	β-Sheet	Donor	Acceptor	|h3JNC’| (Hz)	σ |h3JNC’| (Hz)	Donor	Acceptor	|h3JNC’| (Hz)	σ |h3JNC’| (Hz)	Donor	Acceptor	|h3JNC’| (Hz)	σ |h3JNC’| (Hz)
1	β1-β2	707	724	0.60	0.0074	113	130	0.76	0.020	116	133	0.87	0.015
2	β1-β2	724	708	Peak overlap		130	114	0.53	0.051	133	117	0.59	0.024
3	β1-β2	710	722	0.70	0.0077	116	128	0.65	0.027	119	131	Peak overlap
4	β1-β2	722	710	0.50	0.019	128	116	Peak overlap		131	119	0.46	0.020
5	β1-β2	712	720	No HNCO peak		118	126	0.53	0.056	121	129	0.57	0.014
6	β1-β2	719	713	Peak overlap		125	118	0.66	0.026	128	121	0.62	0.017
7	β2-β3	723	735	H-bond peak present. but too weak to quantify		129	142	0.41	0.029	132	145	0.42	0.019
8	β2-β3	735	723	Peak overlap		142	129	0.70	0.019	145	132	0.69	0.027
9	β2-β3	725	734	0.71	0.010	131	140	0.48	0.032	134	143	0.61	0.036
10	β2-β3	733	726	–	–	140	132	0.96	0.021	143	135	1.0	0.011
11	β2-β3	728	731	0.61	0.012	134	138	–	–	137	141	–	–
12	β3-β4	732	745	0.59	0.009	139	154	0.60	0.034	142	157	Peak overlap
13	β3-β4	745	732	0.62	0.019	154	139	No HNCO peak		157	142	0.68	0.015
14	β3-β4	734	743	0.69	0.039	141	152	0.65	0.049	144	155	0.58	0.019
15	β3-β4	743	734	0.49	0.029	152	141	–	–	155	144	0.72	0.021
16	β3-β4	736	741	0.63	0.033	143	150	0.75	0.033	146	153	0.49	0.024
17	β3-β4	741	736	No H-bond orientation		150	143	0.47	0.052	153	146	0.48	0.015
18	β3-β4	No equivalent		–	–	148	145	No H-bond orientation		151	148	No HNCO peak
19	β5-β1	713	749	No HNCO peak		119	158	Peak overlap		122	161	–	–
20	β5-β1	751	711	–	–	160	117	0.51	0.036	163	120	0.57	0.037
21	β5-β1	711	751	0.68	0.023	117	160	0.68	0.015	120	163	0.53	0.016
22	β5-β1	753	709	–	–	162	115	–	–	165	118	–	–
23	β5-β1	No equivalent		–	–	No equivalent		–	–	No equivalent		–	–
24	β5-β1	No equivalent		–	–	No equivalent		–	–	No equivalent		–	–