Table 1.

Statistics of data collection and structural refinement of 1918H1 HA mutants

	DH1 HA-6’SLN	DH1D HA-6’SLN	DH1E HA-6’SLN	DH1E HA-3’SLN

*Data collection statistics*

Wavelength (Å)	0.97872	0.97856	0.97856	0.97856

Resolution range (Å)	48.74~2.15 (2.27~2.15)	54.47~2.35 (2.48~2.35)	45.69~2.45 (2.58~2.45)	55.38~2.95 (3.11~2.95)

Space group	P 1 21 1	P 1 21 1	P 1 21 1	P 1 21 1

Unit cell
a, b, c (Å)	95.68, 81.82, 121.46	95.75, 80.26, 121.23	95.38, 81.37, 120.96	95.94, 81.05, 120.95
α, β, γ (°)	90, 90.79, 90	90, 91.35, 90	90, 95.45, 90	90, 91.13, 90

Total reflections	436,178 (63,284)	337,887 (48,689)	302,929 (44,056)	142,031 (20,833)

Unique reflections	102,164 (14,841)	76,785 (11,130)	68,049 (9,868)	39,403 (5,731)

Multiplicity	4.3 (4.3)	4.4 (4.4)	4.5 (4.5)	3.6 (3.6)

Completeness (%)	100.0 (100.0)	100.0 (99.9)	100.0 (100.0)	100.0 (100.0)

Mean I/sigma(I)	9.4 (2.6)	9.1 (2.6)	10.3 (2.5)	6.9 (2.0)

Wilson B-factor (Å²)	25.0	31.3	36.5	50.6

R_merge	0.139 (0.515)	0.138 (0.510)	0.142 (0.573)	0.212 (0.679)

Refinement statistics

R_work	0.182 (0.220)	0.199 (0.226)	0.199 (0.244)	0.213 (0.285)

R_free	0.208 (0.263)	0.236 (0.262)	0.228 (0.270)	0.250 (0.340)

Number of non-hydrogen atoms	13,012	12,566	12,382	11,594

Macromolecules	11,403	11,402	11,393	11,393

Ligands	260	246	216	201

Water	1,349	918	773	—

Protein residues	1,472	1,472	1,470	1,469

RMS

Bonds (Å)	0.006	0.005	0.007	0.005

Angles (°)	1.20	1.15	1.24	1.17

Ramachandran

Favored (%)	98.13	97.99	98.54	98.41

Allowed (%)	1.87	1.94	1.39	1.59

Outliers (%)	0.00	0.07	0.07	0.00

Clashscore	2.81	3.52	3.04	2.56

Average B-factor (Å²)	33.00	36.79	35.85	38.61

Macromolecules	32.21	36.73	35.65	38.46
Ligands	42.65	46.31	47.87	46.73

Water	37.89	35.02	35.41	—

PDB accession code	5VMC	5VMF	5VMG	5VMJ

Statistics for the highest-resolution shell are shown in parentheses.