Send to

Choose Destination
See comment in PubMed Commons below
Proc Natl Acad Sci U S A. 2009 Oct 27;106(43):18195-200. doi: 10.1073/pnas.0909287106. Epub 2009 Oct 12.

Multistart simulated annealing refinement of the crystal structure of the 70S ribosome.

Author information

  • 1Center for Molecular Biology of RNA and Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064, USA.


A macromolecular X-ray crystal structure is usually represented as a single static model with a single set of temperature factors representing a simple approximation of motion and disorder of the structure. Multiconformer representations of small proteins have been shown to better describe anisotropic motion and disorder and improve the quality of their electron density maps. Here, we apply multistart simulated annealing crystallographic refinement to a 70S ribosome-RF1 translation termination complex that was recently solved at 3.2 A resolution. The analysis improves the interpretability of the electron density map of this 2.5-MDa ribonucleoprotein complex and provides insights into its structural dynamics. We also used multistart refinement and conventional Fourier difference maps to address a recent study in which cross-crystal averaging between two crystal forms of the 70S ribosome was used to evaluate reported differences between two ribosome crystal structures solved at 2.8 and 3.7 A resolution. Our analysis suggests that results obtained from cross-crystal averaging are inherently biased toward the higher-resolution dataset.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk