Pushing the boundaries of molecular replacement with maximum likelihood

8/27/99


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Table of Contents

Pushing the boundaries of molecular replacement with maximum likelihood

Why improve molecular replacement?

Why maximum likelihood?

Principle of maximum likelihood

Structure factor probabilities

Amplitude probability distribution

Likelihood-based translation

Translation vs. rotation

Translating oriented molecule

Orientation effect on molecular transform

Orientation effect on structure factor

Rotation function probability distribution

Molecular transform random walk

Levels of approximation for rotation likelihood function: Fourier-Bessel

Levels of approximation for rotation likelihood function: Rice-like

Levels of approximation for rotation likelihood function: Wilson

Rice-like approximation

Why are more molecules difficult?

Calibrating the likelihood functions

Defining an a priori Sigma(A) curve

Implementation of likelihood-based molecular replacement

Rotation tests on Streptomyces griseus trypsin

Translation tests on Streptomyces griseus trypsin

Haloferax volcanii dihydrofolate reductase

DHFR molecular replacement tests

Advantages of likelihood-based molecular replacement

Future work

Author: Randy J. Read

Email: rjr27@cam.ac.uk

Home Page: http://perch.cimr.cam.ac.uk

Other information:
Presentation given at 1999 IUCr meeting in Glasgow. Converted using PowerPoint->HTML option