Original scientific paper

Crystallographic MAD Phasing Strategies Explored Using ELETTRA Sincrotrone Mn K-Edge Data to 2.1 Å and Use of CHESS Establishes the Diffraction Resolution Limit as 0.92 Å for the Protein Mn, Ca Concanavalin A

Nicola S. Hunter ; Section of Structural Chemistry, Department of Chemistry, University of Manchester, M13 9PL, UK
Thomas J. Gleichmann ; Section of Structural Chemistry, Department of Chemistry, University of Manchester, M13 9PL, UK
Madeleine Helliwell ; Section of Structural Chemistry, Department of Chemistry, University of Manchester, M13 9PL, UK
Luisa Barba ; Istituto di Strutturista Chimica, CNR, Stada Statale 14, Km 163.5, Basovizza, 34102 Trieste, Italy
Edoardo Busetto ; Sincrotrone Trieste, Stada Statale 14, Km 163.5, Basovizza, 34102 Trieste, Italy
Andrea Lausi ; Sincrotrone Trieste, Stada Statale 14, Km 163.5, Basovizza, 34102 Trieste, Italy
Helen J. Price ; Section of Structural Chemistry, Department of Chemistry, University of Manchester, M13 9PL, UK
John R. Helliwell ; Section of Structural Chemistry, Department of Chemistry, University of Manchester, M13 9PL, UK

Abstract

Multiwavelength anomalous dispersion (MAD) data have been collected from a single crystal of the protein concanavalin A so as to evaluate different combinations of wavelengths for crystallographic structure determination. Data were recorded to 2.1 Å resolution on a flash frozen crystal at three wavelengths about the Mn K-edge (1.8951 Å, 1.8940 Å, 1.800 Å) using synchrotron radiation at ELETTRA's Sincrotrone Trieste 'XRD' beamline. This is one of the longest wavelength K-edge MAD studies undertaken to date. Anomalous and dispersive Patterson maps are seen to be of high quality and indicate a high occupancy for the manganese binding site. This is confirmed also in the MAD phase determination and electron density maps. Finally 0.92 Å data recorded at CHESS indicates the prospects available for combined phasing strategies based on MAD to medium/high resolution along with ultra high resolution data.

Keywords

Mn; Ca concanavalin A; protein crystallography; MAD phasing; ultra-high resolution; ELETTRA sincrotrone; CHESS synchrotron; Mn K-edge; lectin protein; direct methods in protein crystallography

Hrčak ID:

132264

URI

https://hrcak.srce.hr/132264

Publication date:

1.9.1999.

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