TY  - JOUR
AU  - Brunger, A.T.
AU  - Adams, P.D.
AU  - Fromme, P.
AU  - Fromme, R.
AU  - Levitt, M.
AU  - Schröder, G.F.
TI  - Improving the accuracy of macromolecular structure refinement at 7 Å resolution
JO  - Structure
VL  - 20
SN  - 0969-2126
CY  - London [u.a.]
PB  - Elsevier Science
M1  - PreJuSER-111909
SP  - 957 - 966
PY  - 2012
N1  - Record converted from VDB: 16.11.2012
AB  - In X-ray crystallography, molecular replacement and subsequent refinement is challenging at low resolution. We compared refinement methods using synchrotron diffraction data of photosystem I at 7.4 Å resolution, starting from different initial models with increasing deviations from the known high-resolution structure. Standard refinement spoiled the initial models, moving them further away from the true structure and leading to high R(free)-values. In contrast, DEN refinement improved even the most distant starting model as judged by R(free), atomic root-mean-square differences to the true structure, significance of features not included in the initial model, and connectivity of electron density. The best protocol was DEN refinement with initial segmented rigid-body refinement. For the most distant initial model, the fraction of atoms within 2 Å of the true structure improved from 24% to 60%. We also found a significant correlation between R(free) values and the accuracy of the model, suggesting that R(free) is useful even at low resolution.
KW  - Bacterial Proteins: chemistry
KW  - Crystallography, X-Ray
KW  - Models, Molecular
KW  - Photosystem I Protein Complex: chemistry
KW  - Protein Structure, Secondary
KW  - Protein Structure, Tertiary
KW  - Software
KW  - Structural Homology, Protein
KW  - Bacterial Proteins (NLM Chemicals)
KW  - Photosystem I Protein Complex (NLM Chemicals)
LB  - PUB:(DE-HGF)16
C6  - pmid:22681901
C2  - pmc:PMC3380535
UR  - <Go to ISI:>//WOS:000305094500004
DO  - DOI:10.1016/j.str.2012.04.020
UR  - https://juser.fz-juelich.de/record/111909
ER  -