2blq

Elastase After A High Dose X-Ray "Burn"

spinqualitylabelsall models 2blq, resolution 1.33Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2blq is a 1 chain structure with sequence from Sus scrofa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.33Å Ligands: CA, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Specific radiation damage can be used to solve macromolecular structures using the radiation-damage-induced phasing (RIP) method. The method has been investigated for six disulfide-containing test structures (elastase, insulin, lysozyme, ribonuclease A, trypsin and thaumatin) using data sets that were collected on a third-generation synchrotron undulator beamline with a highly attenuated beam. Each crystal was exposed to the unattenuated X-ray beam between the collection of a 'before' and an 'after' data set. The X-ray 'burn'-induced intensity differences ranged from 5 to 15%, depending on the protein investigated. X-ray-susceptible substructures were determined using the integrated direct and Patterson methods in SHELXD. The best substructures were found by downscaling the 'after' data set in SHELXC by a scale factor K, with optimal values ranging from 0.96 to 0.99. The initial substructures were improved through iteration with SHELXE by the addition of negatively occupied sites as well as a large number of relatively weak sites. The final substructures ranged from 40 to more than 300 sites, with strongest peaks as high as 57sigma. All structures except one could be solved: it was not possible to find the initial substructure for ribonuclease A, however, SHELXE iteration starting with the known five most susceptible sites gave excellent maps. Downscaling proved to be necessary for the solution of elastase, lysozyme and thaumatin and reduced the number of SHELXE iterations in the other cases. The combination of downscaling and substructure iteration provides important benefits for the phasing of macromolecular structures using radiation damage. Improving radiation-damage substructures for RIP.,Nanao MH, Sheldrick GM, Ravelli RB Acta Crystallogr D Biol Crystallogr. 2005 Sep;61(Pt 9):1227-37. Epub 2005, Aug 16. PMID:16131756 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Elastase 3D structures

Proteopedia Page Contributors and Editors (what is this?)

OCA