2ID8

What can be done with a good crystal and an accurate beamline?

(2006) Acta Crystallogr D Biol Crystallogr 62: 1475-1483

• PubMed: 17139083 Search on PubMed
• DOI: https://doi.org/10.1107/S0907444906038534
• Primary Citation of Related Structures:  
  2ID8


• PubMed Abstract: 
  

  X-ray single-wavelength anomalous diffraction (SAD) data from a crystal of proteinase K were collected using synchrotron radiation of 0.98 A wavelength at SER-CAT 22-ID beamline, Advanced Photon Source, Argonne National Laboratory. At this wavelength, the expected Bijvoet ratio resulting from the presence of one calcium, one chloride and ten S atoms in the 279-residue protein is extremely small at approximately 0.46%. The direct-methods program SHELXD located 11 anomalous sites using data truncated to 2 A resolution. SHELXE was used to produce an easily interpretable electron-density map. This study shows that an accurate beamline and a good-quality crystal provide the possibility of successfully using a very weak anomalous signal of sulfur measured at a short wavelength for phasing a protein structure, even if a small degree of radiation damage is present.

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Organizational Affiliation: 

SAIC-Frederick Inc., Basic Research Program, Argonne National Laboratory, Argonne, IL 60439, USA.