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1n4f
From Proteopedia
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| , resolution 1.78Å | |||||||
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| Ligands: | , , | ||||||
| Activity: | Lysozyme, with EC number 3.2.1.17 | ||||||
| Related: | 1B0D
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Para-Arsanilate Derivative of Hen Egg-White Lysozyme
Overview
Single/multiple-wavelength anomalous dispersion (SAD/MAD) experiments were performed on a crystal of an organic arsenic derivative of hen egg-white lysozyme. A para-arsanilate compound used as a crystallizing reagent was incorporated into the ordered solvent region of the lysozyme molecule. Diffraction data were collected to high resolution (</=2.0 A) at three wavelengths around the K edge (1.04 A) of arsenic at beamline BM30A, ESRF synchrotron. Anomalous Patterson maps clearly showed the main arsanilate site to be between three symmetry-related lysozyme molecules, at a location previously occupied by a para-toluenesulfonate anion. MAD phases at 2 A derived using the program SHARP led to an electron-density map of sufficient quality to start manual building of the protein model. Amplitudes from a second crystal measured to a resolution of 1.8 A at the peak wavelength revealed two additional heavy-atom sites, which reinforced the anomalous subset model and therefore dramatically improved the phasing power of the arsenic derivative. The subsequent solvent-flattened map was of such high accuracy that the program ARP/wARP was able to build a nearly complete model automatically. This work emphasizes the great potential of arsenic for de novo structure determination using anomalous dispersion methods.
About this Structure
1N4F is a Single protein structure of sequence from Gallus gallus. Full crystallographic information is available from OCA.
Reference
Phasing power at the K absorption edge of organic arsenic., Retailleau P, Prange T, Acta Crystallogr D Biol Crystallogr. 2003 May;59(Pt 5):887-96. Epub 2003, Apr 25. PMID:12777806
Page seeded by OCA on Sun Mar 30 22:25:14 2008
