Table S1.
Statistics for X-ray crystallographic data collection and model refinement
| Statistic | Value |
| Data collection | |
| Source | SSRF-BL17U |
| Space group | P 31 1 2 |
| Unit cell parameters | |
| a, b, c (Å) | a = 72.824, b = 72.824, c = 116.360 |
| α, β, γ, o | α = 90.00, β = 90.00, γ = 120.00 |
| Resolution range, Å | 50.00–2.50 (2.54–2.50) |
| No. of unique reflections | 12,561 (608) |
| Redundancy | 6.3 (6.5) |
| I/σ(I) | 35.2 (4.8) |
| Completeness (%) | 99.9 (100.0) |
| Rmerge (%)* | 6.8 (60.8) |
| Wilson_B | 49.5 |
| Structure refinement | |
| Resolution, Å | 42.7–2.49 (2.75–2.49) |
| Rwork†/Rfree‡ % | 18.30 (27.94)/25.06(38.62) |
| rmsd bonds (Å/angles) ° | 0.008/1.010 |
| Number of reflections | |
| Working set | 11,914 |
| Test set | 610 |
| Number of protein atoms | 2,137 |
| Number of water atoms | 95 |
| Average B factor (Å2) | |
| Protein (main chain) | 59.3 (61.7) |
| Water | 33.8 |
| Ramachandran plot (%) | |
| Most favored regions | 98.1 |
| Additionally allowed | 1.9 |
| Generously allowed | 0 |
Numbers in parentheses represent the value for the highest-resolution shell.
*
Rmerge = ∑|Ii − Im|/∑Ii, where Ii is the intensity of the measured reflection and Im is the mean intensity of all symmetry- related reflections.
†
Rcryst = Σ||Fobs| − |Fcalc||/Σ|Fobs|, where Fobs and Fcalc are the observed and calculated structure factors.
‡
Rfree = ΣT||Fobs| − |Fcalc||/ΣT|Fobs|, where T is a test dataset of ∼5% of the total reflections chosen randomly and set aside before refinement.