Table 1A.
Summary of crystallographic analysis for GAB protein
| Multiple isomorphous replacement | |||
| Native (high) | 5 mM HgAc | 2 mM thimerosal | |
| dMin/λ (Å) | 20–2.0/0.9878 | 20–2.0/0.9878 | 20–2.0/0.9878 |
| No. of sites | — | 2 | 2 |
| Rsyma (%) a overall (outer shell) | 7.9 (23.9) | 4.9 (15.5) | 6.3 (19.8) |
| Coverage (%) overall (outer shell) | 96.9 (94.1) | 95.8 (94.9) | 74.8 (52.1) |
| I/σ (I) overall (outer shell) | 13.0 (4.2) | 9.9 (3.8) | 9.1 (4.8) |
| Reflections (total/unique) | 442,770/33,222 | 446,316/32,810 | 562,379/25,609 |
| Phasing statistics | |||
| MFIDb (%) | 16.0 | 28.1 | |
| Overall phasing powerc (centric/acentric) | 1.25/1.18 | 0.74/1.07 | |
| Mean FOMd (centric/acentric) | 0.358/0.371 | ||
| Mean FOMd after Solomon | 0.63 | ||
| Refinement | |||
| Resolution range | 20–2.0 | ||
| No. of reflections >0.0σ | 33216 | ||
| Total no. atoms/water/Fe(II) | 490/320/1 | ||
| Re/Rfreef | 0.193/0.240 | ||
| Rmsdg bond (Å)/angles(°)/B(Å2) | 0.009/1.8/1.63 | ||
a Rsym = ∑|I-〈I〉|/∑ I, where I = observed intensity, and 〈I〉 = average intensity.
b MFID (mean fractional isomorphous difference) = ∑∥Fph|-|Fp∥/∑|Fp|, where Fp = protein structure factor amplitude and |Fph| = heavy-atom derivative structure factor amplitude.
c Phasing power = root mean square (|Fh|/E, where |Fh| = heavy-atom structure factor amplitude and E = residual lack of closure error.
d Mean FOM = combined figure of merit.
e R based on 95% of the data used in refinement.
f R based on 5% of the data withheld for the cross-validation test.
g Root mean square deviation of bond lengths, angles, and B factors. Rmsd B is combined for side chain/main chain.
Rc = ∑∥Fh(obs)|-|Fh(calc)∥/∑|Fh(obs)| for centric reflections where |Fh(obs)| = observed heavy-atom structure factor amplitude, and |Fh(calc)| = calculated heavy-atom structure factor amplitude.