SAD or MAD phasing: location of the anomalous scatterers.
The method of joint probability distribution functions is applied in order to estimate the structure-factor moduli of the anomalous scatterer substructure both in the SAD (single-wavelength anomalous dispersion) and in the MAD (multi-wavelength anomalous dispersion) cases. The experimental data |F(1)(+)|, |F(1)(-)|, ..., |F(n)(+)|, |F(n)(-)| measured at n wavelengths are used simultaneously to estimate the value of |F(oa)| arising from the normal scattering of the anomalous scatterers. A practical procedure is described that, when applied to the experimental diffraction data of several proteins, shows robustness and efficiency.
Burla
Maria Cristina
MC
Dipartimento di Scienza della Terra, Piazza Università, Perugia, Italy.
Carrozzini
Benedetta
B
Cascarano
Giovanni Luca
GL
Giacovazzo
Carmelo
C
Polidori
Giampiero
G
D000465:Algorithms; D018360:Crystallography, X-Ray; D004798:Enzymes / Q000737:chemistry; D015233:Models, Statistical; D011338:Probability Theory; D012542:Scattering, Radiation
D004798:Enzymes