Recoord 07
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Transcript of Recoord 07
RECOORD
REcalculated COORdinates Database
Nederveen et al., Proteins 2005
Recalculation of > 500 NMR Structures
• decrease user - and software dependent bias • better comparison
• provide database for development of… - validation tools - calculation protocols - statistical approaches - modelling
NMR Data?!?
Three types of restraints:
1. distance restraints (NOEs !!!!)
2. dihedral angle restraints (coupling constants or chemical shift)
3. orientational restaints (RDCs, relaxation data)
NMR Structure Calculation !?!?
XPLOR/CNS: Molecular Dynamics in Cartesian Space Simulated Annealing Refinement (put in solvent!)
DYANA: Torsion Angle Dynamics Simulated Annealing No force field, energy minimisation necessary
Find a model that fits with your data and the known chemistry of your protein!
• used CNS and CYANA for recalculation
• > 8000 processors used
• total CPU time: 31,169h (~3.5 years on single computer!)
How it was done….
• restraints obtained from BMRB database
• water refinement: restrained molecular dynamics (CNS)
• extensive quality assessment (PROCHECK and WHAT-CHECK)
Results
Quality-assessment of recalculated structures
o Packing o Ramachandran appearance
One standard deviation closer to mean!
Results continued…
o Number of restraints per residue o Agreement with experimental restraints o RMSD (positional root mean square deviation) o Comparison CNS and CYANA o Relation NMR data quality and structural quality
Quality-assessment of recalculated structures
CNS vs. CYANA (no water ref.)
Z-score: standard deviation away from the mean
CNS before and after water ref.
Why am I telling you this?
www.ebi.ac.uk/msd-srv/docs/NMR/recoord/main.html
… you can use the scripts!