Likelihood-based estimation of substructure content from single-wavelength anomalous diffraction (SAD) intensity data.

ABSTRACT: SAD phasing can be challenging when the signal-to-noise ratio is low. In such cases, having an accurate estimate of the substructure content can determine whether or not the substructure of anomalous scatterer positions can successfully be determined. Here, a likelihood-based target function is proposed to accurately estimate the strength of the anomalous scattering contribution directly from the measured intensities, determining a complex correlation parameter relating the Bijvoet mates as a function of resolution. This gives a novel measure of the intrinsic anomalous signal. The SAD likelihood target function also accounts for correlated errors in the measurement of intensities from Bijvoet mates, which can arise from the effects of radiation damage. When the anomalous signal is assumed

SUBMITTER: Hatti KS 

PROVIDER: S-EPMC8251343 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature