1gqb
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HUMAN MIR-RECEPTOR, REPEAT 11
OverviewOverview
Improved data quality now makes it feasible to exploit the weak anomalous, signal derived only from the sulfurs inherent to the protein or in, particular from halide ions incorporated by soaking. The latter technique, requires the location of a high number of partially occupied halide sites., This number appears to be roughly proportional to the exposed protein, surface. This paper explores the application of dual-space ab initio, methods as implemented in the program SHELXD to the location of, substructures of sulfur in SAD experiments, bromide in SAD and MAD, experiments and iodide using SAD and SIRAS to determine the anomalous-atom, substructure. Sets of atoms consistent with the Patterson function were, generated as a starting point for the dual-space recycling procedure in, SHELXD. The substructure is then expanded to the full structure by, maximum-likelihood phasing with SHARP and density modification with the, program DM. Success in the location of the substructures and subsequent, phasing depends critically on the quality of the data and on the extent of, the anomalous signal. This varies with each crystal and soak, but for the, same crystal the significance of the anomalous signal was found to be, highly sensitive to the redundancy of the intensity measurements, which in, some cases made all the difference. This is illustrated by the, determination of the previously unknown structure of repeat 11 of the, human mannose-6-phosphate/insulin-like growth factor II receptor, (Man6P/IGFII-receptor), with 310 amino acids in the asymmetric unit, which, was phased by soaking the crystals in a cryoprotectant solution containing, halide anions.
DiseaseDisease
Known diseases associated with this structure: Hepatocellular carcinoma OMIM:[147280]
About this StructureAbout this Structure
1GQB is a Single protein structure of sequence from Homo sapiens with BR as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Locating the anomalous scatterer substructures in halide and sulfur phasing., Uson I, Schmidt B, von Bulow R, Grimme S, von Figura K, Dauter M, Rajashankar KR, Dauter Z, Sheldrick GM, Acta Crystallogr D Biol Crystallogr. 2003 Jan;59(Pt 1):57-66. Epub 2002, Dec 19. PMID:12499540
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