Table 1

X-ray data collection and refinement statistics for unliganded and peptide-bound AP33 Fab

StatisticValue for AP33 Faba
AP33 FabAP33 Fab complex with peptide 8834AP33 Fab complex with peptide 8741
Data collection
    Space groupI 41 2 2C 2C 2
    Unit cell dimensions (Å)/(°)a = 90.9, b = 90.9, c = 459.1a = 171.9, b = 40.7, c = 73.8a = 127.6, b = 56.9, c = 81.8
α = β = γ = 90α = γ = 90, β = 112.1α = γ = 90, β = 113.9
    Resolution range (Å)21.6–2.65 (2.8–2.65)20–2.5 (2.64–2.51)50–1.80 (1.83–1.80)
    No. of unique observations27,78916,45549,204
    Completeness (%)97.4 (86.8)99.3 (96.8)98.4 (81.0)
    Redundancy6.2 (5.8)3.5 (3.1)3.5 (2.4)
    Rmerge (%)b10.0 (35.5)6.0 (48.0)3.8 (15.8)
    〈I/σI〉12.3 (4.1)14 (2.3)45.6 (8.1)
Refinement
    No. of Fab atoms6,5213,2833,316
    No. of peptide atoms87108
    Avg B factors (Å2)
        Fab/peptide40.8e45.5/43.124.1/22.3
        Rcrystc24.724.417.8
        Rfreed31.932.021.1
    RMSD bond distance (Å)0.0130.0160.028
    RMSD bond angle (°)1.611.682.24
  • a Numbers in parentheses refer to the highest-resolution shell.

  • b Rmerge = ∑hkli | Ihkl, i − 〈Ihkl〉|/∑hklIhkl〉, where 〈Ihkl〉 is the average of symmetry-related observations of a unique reflection.

  • c Rcryst = (∑ | |Fo| − |Fc| |)/(∑ |Fo|).

  • d Test set comprised 5% of reflections.

  • e Value for Fab.