Table S1.

Summary of X-ray diffraction data and structure refinement statistics

Crystal	Hg derivate	MORC3+AMPPNP+H3(1–15)K4me3	MORC3+AMPPNP+H3(1–32)
Summary of diffraction data
Beamline	SSRF-BL17U1	SSRF-BL17U1	SSRF-BL19U
PDB ID code		5IX1	5IX2
Wavelength, Å	0.9928	0.9792	0.9792
Space group	I222	I222	I222
Cell parameters, Å
a	110.9	111.4	112.2
b	151.6	149.1	147.5
c	174.1	173.5	173.6
Resolution, Å	50.0–2.9 (3.00–2.90)*	20.0–2.6 (2.74–2.60)	20.0–2.9 (3.06–2.90)
Rmerge, %	13.4 (70.1)	8.5 (86.6)	9.1 (70.1)
Observed reflections	479,105	205,990	206,638
Unique reflections	33,002	44,534	32,131
Average I/σ(I)	34.6 (4.2)	11.8 (2.0)	12.5 (2.6)
Completeness, %	99.9 (100.0)	99.7 (99.9)	99.6 (99.8)
Redundancy	14.5 (14.9)	6.4 (5.9)	6.3 (6.9)
Refinement and structure model
R/Free R factor, %		21.8/23.0	22.0/23.6
Non-H atoms		7,042	7,049
Protein/peptide		6,751/158	6,825/158
AMPPNP/water		62/67	62/-
Zn2+/Mg2+		2/2	2/2
B factor, Å2		75.7	80.2
Protein/peptide		75.4/93.0	79.9/101.0
AMPPNP/water		65.5/72.7	62.9/-
Zn2+/Mg2+		87.9/59.1	88.5/58.9
Rmsd
Bond lengths, Å		0.020	0.022
Bond angles, °		1.790	1.871

SSRF, Shanghai Synchrotron Radiation Facility.

^*Values in parentheses are for the highest shell.