Bookmark and Share

X-Ray Crystallography Deliverables

Crystals

  1. Unliganded - We have set up a number of crystal screens and identified a condition or conditions, which produce crystals. They might be salt, but at least we have an initial lead or leads.
  2. Complex with ligand or lead compound - Via either co-crystallization or soaking, we have attempted to incorporate your compound of interest into a crystal of your target protein.

Initial diffraction experiments

  1. Salt or protein (SBXX) - Screened an initial diffraction image or two to make sure it is not a salt crystal
  2. Native data (SBXD) - Collected a complete native data set. Indexed the data to determine the space group, integrated and scaled the data to the best of our ability (we can’t make bad data look good).
  3. Derivative or selenomethionine data (SBXD) - Collected a complete data set at the appropriate wavelength where applicable (i.e. the synchrotron). Indexed the data to determine the space group, integrated and scaled the data to the best of our ability (we can’t make bad data look good).
  4. Data for putative lead compound or ligand complex (SBXD) - Collected a complete data set for the putative complex. Indexed the data to determine the space group, integrated and scaled the data to the best of our ability (we can’t make bad data look good).

Preliminary structure solution (SBXP)

  1. Molecular Replacement - We identified and created an appropriate search model, and used one of several up-to-date program packages (Molrep, Phaser, BALBES, etc.) to obtain a preliminary molecular replacement solution as judged by the statistical criteria used for the program of choice (Typically Correlation Coefficient or Z-score).
  2. SIRAS/SAD/MIRAS/MAD - Using the data collected in 2c, we have obtained a preliminary solution for the experimental phases for your data as judged by visual inspection of electron density maps after density modification.

Model building, refinement, and validation (SBXR)

  1. The end product for this deliverable is the best model we can get given the available data, with acceptable R-factor values and acceptable deviations from ideal geometry, ready to be deposited into the RCSB database (i.e., if deposited, will not have errors flagged by the RCSB that need to be corrected). The model will therefore be ready to include in a published manuscript.