Table S3.
Comparison of NMR and crystallographic observations of conformational heterogeneity
| Residue | Apo (X-ray)* | Apo (NMR)† | 3J(Hz) | Chemical shift | Complex (X-ray)* | Complex ρ ratio‡ | Note |
| K4 | χ1: + | χ1: + | 3J(CγC′) = 2.72 ± 0.01 | χ1: + | 0.57 | ||
| K7 | χ1: + | χ1: + | 3J(CγC′) = 2.61 ± 0.01 | χ1: + | 0.45 | ||
| I16 | χ1: − | χ1: − | 3J(Cγ1C′) = 3.95 ± 0.05 | C(δ1) = 13.7 ppm | χ1: − | 0.07 | From NMR scalar coupling and chemical shift: |
| χ2: − | χ2: + | 3J(Cγ1N) = 0.37 ± 0.21; | χ2: − | Population trans 0.80 | |||
| 3J(Cγ2C′) = 1.09 ± 0.01; | Population gauche− 0.20 | ||||||
| 3J(Cγ2N) = 2.10 ± 0.01 | |||||||
| L17§ | χ1: a | χ1: + | 3J(CγC′) = 2.97 ± 0.02 | C(δ1) = 24.7 ppm | χ1: − | 0.24 | |
| χ2: a | χ2: + | 3J(CγN) = 0.74 ± 0.07 | C(δ2) = 23.0 ppm; | χ2: − | |||
| ΔCS = 1.7 ppm | |||||||
| L19 | χ1: − | χ1: − | 3J(CγC′) = 3.80 ± 0.04; | C(δ1) = 26.6 ppm | χ1: − | 0.13 | |
| χ2: a | χ2: + | 3J(CγN) = 0.73 ± 0.20 | C(δ2) = 22.8 ppm; | ||||
| ΔCS = 3.8 ppm | |||||||
| L22 | χ2: − | χ2: − | C(δ1) = 27.2 ppm; | χ2: − | 0.3 | ||
| C(δ2) = 22.2 ppm; | |||||||
| ΔCS = 5.0 ppm | |||||||
| T23 | χ1: − | χ1: + | 3J(Cγ2C′) = 3.06 ± 0.01; 3J(Cγ2N) = 1.08 ± 0.01 | χ1: − | 0.1 | Crystal contact | |
| I31§ | χ1: − | χ1: − | 3J(Cγ1C′) = 3.72 ± 0.03; 3J(Cγ1N) = 0.36 ± 0.20 | C(δ1) = 12.4 ppm | χ1: − | 0.13 | |
| χ2: m | χ2: + | χ2: − | |||||
| L34 | χ2: + | χ2: + | C(δ1) = 25.5 ppm | χ2: + | 0.63 | ||
| C(δ2) = 25.4 ppm; | |||||||
| ΔCS = 0.1 ppm | |||||||
| V40 | χ1: − | χ1: − | 3J(Cγ1C′) = 1.05 ± 0.01; 3J(Cγ1N) = 0.72 ± 0.01; | χ1: − | 0.10 | ||
| 3J(Cγ2C′) = 3.65 ± 0.01; 3J(Cγ2N) = 0.45 ± 0.02 | |||||||
| I44 | χ1: − | χ1: − | 3J(Cγ1C) = 3.60 ± 0.02; 3J(Cγ1N) = 0.52 ± 0.15; 3J(Cδ1Cα) = 2.77 ± 0.01 | C(δ1) = 13.0 ppm | χ1: − | 0.22 | |
| χ2: a | χ2: + | χ2: + | |||||
| L45 | χ1: − | χ1: ? | C(δ1) = 23.8 ppm | χ1: − | 0.26 | From NMR chemical shifts: | |
| χ2: − | χ2: − | C(δ2) = 24.5 ppm; | χ2: − | Population trans 0.43 | |||
| ΔCS = −0.7 ppm | Population gauche+ 0.57 | ||||||
| K49 | χ1: − | χ1: − | 3J(CγC′) = 3.57 ± 0.03 | χ1: − | 0.29 | ||
| χ2: + | χ2: N | χ2: + | |||||
| L51 | χ1: + | χ1: ? | C(δ1),C(δ2) = 24.1 ppm; | χ1: − | 0.44 | ||
| χ2: + | χ2: + | ΔCS = 0 ppm | χ2: + |
*
+, conformational heterogeneity observed in crystal structure; −, no conformational heterogeneity observed; a, anisotropic electron density observed; m, multiple rotamers observed among different apo SpA-domain structures.
†
Dynamic side chains as detected by 3J averaging and/or chemical shift deviations from static limits; +, dynamic χ1 or χ2; −, static χ1 or χ2; N, no observation; ?, ambiguous assignment.
‡
Values close to 0 indicate low conformational heterogeneity; values close to 1 indicate high conformational heterogeneity (see text).
§
Residues that make contact with Fc.