NAME: Peter Zwart

AFFILIATION: Lawrence Berkeley Laboratory, USA

CONTACT: PHZwart@lbl.gov

 

TITLE: "General Pathologies"

ABSTRACT: P.H.Zwart(1), A. Lebedev(2), G. Murshudov(2) & P.D.Adams(1)

 

1): Computational Crystallographic Initiative , Lawrence Berkeley National Laboratories, Berkeley, CA, USA.

2): York Structural Biology Laboratory, University of York, York, UK

 

It is not uncommon for protein crystals to crystallize with more than a single molecule per asymmetric unit. The possibility of a multitude of favorable inter molecular contacts often forms the structural basis for a polymorphism that can result in various pathological situations such as twinning, modulated crystals and pseudo translational or rotational symmetry. The presence of these idiosyncrasies in the data can make molecular replacement challenging, particularly when the assignment of the space group is not unambiguous.

 

We will discuss the implications of these situations to the solution of crystal structures via the molecular replacement method, present tools to identify problems from the diffraction data and present several examples from the literature.