(c).

Substructure.

		Se-atom positions
Se atom	Assignment‡	x	y	z	Occupancy	B (2)
Se1	114	7.633	43.423	130.908	0.67	13.91
Se2	32	21.278	40.258	174.832	1.01	17.67
Se3	71	11.945	45.252	157.659	1.13	17.35
Se4	239	8.759	22.233	85.618	0.76	32.66
Se5	32	21.447	40.333	177.175	0.43	23.73
Se6	71	13.568	45.546	154.124	0.29	24.88
Se7	32	21.723	40.928	173.064	0.65	13.52
Se8	114	7.308	42.994	132.28	0.40	18.28
Se9	114	8.198	41.493	130.306	0.78	16.12
Se10	71	14.044	46.317	160.270	0.25	23.92
Se11	71	14.127	45.675	157.400	0.75	27.37
Se12	239	8.651	21.926	88.321	0.14	20.66
Se13	239	9.436	22.271	83.812	0.27	24.14
Se14	114	8.143	42.011	127.657	0.17	23.33
Se15	32	23.676	41.008	174.627	0.46	20.70
Se16	32	21.241	40.620	170.453	0.28	26.26
Se17	32	20.222	40.251	172.839	0.43	14.92
Se18	32	20.993	40.401	179.738	0.21	22.43

^† R _meas = , where N(hkl) is the multiplicity.

^‡Several Se atoms clustered around four selenomethionine residues at positions 32, 71, 114 and 239 of CsuC.