Imperial College London
Alternate

DrJamesMurray

Faculty of Natural Sciences, Department of Life Sciences

Senior Lecturer
 
 
 
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Contact

 

+44 (0)20 7594 8895j.w.murray Website

 
 
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Location

 

706Sir Ernst Chain BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Jamshidiha:2019:10.1107/s2059798318017825,
author = {Jamshidiha, M and Pérez-Dorado, I and Murray, JW and Tate, EW and Cota, E and Read, RJ},
doi = {10.1107/s2059798318017825},
journal = {Acta Crystallographica Section D Structural Biology},
pages = {342--353},
title = {Coping with strong translational noncrystallographic symmetry and extreme anisotropy in molecular replacement with Phaser: human Rab27a},
url = {http://dx.doi.org/10.1107/s2059798318017825},
volume = {75},
year = {2019}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Data pathologies caused by effects such as diffraction anisotropy and translational noncrystallographic symmetry (tNCS) can dramatically complicate the solution of the crystal structures of macromolecules. Such problems were encountered in determining the structure of a mutant form of Rab27a, a member of the Rab GTPases. Mutant Rab27a constructs that crystallize in the free form were designed for use in the discovery of drugs to reduce primary tumour invasiveness and metastasis. One construct, hRab27a<jats:sup>Mut</jats:sup>, crystallized within 24h and diffracted to 2.82Å resolution, with a unit cell possessing room for a large number of protein copies. Initial efforts to solve the structure using molecular replacement by <jats:italic>Phaser</jats:italic> were not successful. Analysis of the data set revealed that the crystals suffered from both extreme anisotropy and strong tNCS. As a result, large numbers of reflections had estimated standard deviations that were much larger than their measured intensities and their expected intensities, revealing problems with the use of such data at the time in <jats:italic>Phaser</jats:italic>. By eliminating extremely weak reflections with the largest combined effects of anisotropy and tNCS, these problems could be avoided, allowing a molecular-replacement solution to be found. The lessons that were learned in solving this structure have guided improvements in the numerical analysis used in <jats:italic>Phaser</jats:italic>, particularly in identifying diffraction measurements that convey very little information content. The calculation of information content could also be applied as an alternative to ellipsoidal truncation. The post-mortem analysis also revealed an oversight in accounting for measurement errors in the fast rotation function. While the crystal of mutant Rab27a is not amenable to drug screening, the structure can guide new modifications to obtain more sui
AU  - Jamshidiha,M
AU  - Pérez-Dorado,I
AU  - Murray,JW
AU  - Tate,EW
AU  - Cota,E
AU  - Read,RJ
DO  - 10.1107/s2059798318017825
EP  - 353
PY  - 2019///
SN  - 2059-7983
SP  - 342
TI  - Coping with strong translational noncrystallographic symmetry and extreme anisotropy in molecular replacement with Phaser: human Rab27a
T2  - Acta Crystallographica Section D Structural Biology
UR  - http://dx.doi.org/10.1107/s2059798318017825
UR  - http://hdl.handle.net/10044/1/69634
VL  - 75
ER  -
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