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Native SAD is maturing.

Rose JP, Wang BC, Weiss MS - IUCrJ (2015)

Bottom Line: Today, native SAD sits on the verge of becoming a 'first-choice' method for both de novo and molecular-replacement structure determination.This article will focus on advances that have caught the attention of the community over the past five years.It will also highlight both de novo native SAD structures and recent structures that were key to methods development.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, University of Georgia , Athens, Georgia, USA.

ABSTRACT
Native SAD phasing uses the anomalous scattering signal of light atoms in the crystalline, native samples of macromolecules collected from single-wavelength X-ray diffraction experiments. These atoms include sodium, magnesium, phosphorus, sulfur, chlorine, potassium and calcium. Native SAD phasing is challenging and is critically dependent on the collection of accurate data. Over the past five years, advances in diffraction hardware, crystallographic software, data-collection methods and strategies, and the use of data statistics have been witnessed which allow 'highly accurate data' to be routinely collected. Today, native SAD sits on the verge of becoming a 'first-choice' method for both de novo and molecular-replacement structure determination. This article will focus on advances that have caught the attention of the community over the past five years. It will also highlight both de novo native SAD structures and recent structures that were key to methods development.

No MeSH data available.


A photograph of the PILATUS 12M detector (courtesy of DECTRIS) installed on beamline I23 at the Diamond Light Source. The custom curved detector will be used to collect native SAD data up to the sulfur edge (λ = 5.01 Å), where the sulfur anomalous signal Δf′′ is 4.1 e−. The detector has been designed to operate in a vacuum since the entire I23 endstation sits in a vacuum vessel to reduce air absorption. The curved detector allows access to diffraction data up to 2θ = ±100°.
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fig5: A photograph of the PILATUS 12M detector (courtesy of DECTRIS) installed on beamline I23 at the Diamond Light Source. The custom curved detector will be used to collect native SAD data up to the sulfur edge (λ = 5.01 Å), where the sulfur anomalous signal Δf′′ is 4.1 e−. The detector has been designed to operate in a vacuum since the entire I23 endstation sits in a vacuum vessel to reduce air absorption. The curved detector allows access to diffraction data up to 2θ = ±100°.

Mentions: In the United Kingdom, researchers are commissioning beamline I23 at the Diamond Light Source for long-wavelength crystallography. The beamline has been specifically designed for native SAD experiments and will provide stable X-rays in the range from 1.5 to 4 Å [Δf′′(S) = 3.06 e−]. To reduce X-ray absorption and scattering effects, the entire experiment will be carried out in vacuo using the DECTRIS PILATUS 12M, a large semi-cylindrical hybrid photon-counting detector (Marchal & Wagner, 2011 ▸) designed to reduce parallax at these wavelengths (Fig. 5 ▸). Frozen crystals will be introduced into the vacuum chamber and mounted using a custom magnetic joint-based sample holder adapted from similar devices used in cryo­electron microscopy (Mykhaylyk & Wagner, 2013 ▸). X-ray tomography will be used to determine the dimensions of the crystal for empirical absorption corrections. The first data sets from the beamline are expected in early 2015.


Native SAD is maturing.

Rose JP, Wang BC, Weiss MS - IUCrJ (2015)

A photograph of the PILATUS 12M detector (courtesy of DECTRIS) installed on beamline I23 at the Diamond Light Source. The custom curved detector will be used to collect native SAD data up to the sulfur edge (λ = 5.01 Å), where the sulfur anomalous signal Δf′′ is 4.1 e−. The detector has been designed to operate in a vacuum since the entire I23 endstation sits in a vacuum vessel to reduce air absorption. The curved detector allows access to diffraction data up to 2θ = ±100°.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4491315&req=5

fig5: A photograph of the PILATUS 12M detector (courtesy of DECTRIS) installed on beamline I23 at the Diamond Light Source. The custom curved detector will be used to collect native SAD data up to the sulfur edge (λ = 5.01 Å), where the sulfur anomalous signal Δf′′ is 4.1 e−. The detector has been designed to operate in a vacuum since the entire I23 endstation sits in a vacuum vessel to reduce air absorption. The curved detector allows access to diffraction data up to 2θ = ±100°.
Mentions: In the United Kingdom, researchers are commissioning beamline I23 at the Diamond Light Source for long-wavelength crystallography. The beamline has been specifically designed for native SAD experiments and will provide stable X-rays in the range from 1.5 to 4 Å [Δf′′(S) = 3.06 e−]. To reduce X-ray absorption and scattering effects, the entire experiment will be carried out in vacuo using the DECTRIS PILATUS 12M, a large semi-cylindrical hybrid photon-counting detector (Marchal & Wagner, 2011 ▸) designed to reduce parallax at these wavelengths (Fig. 5 ▸). Frozen crystals will be introduced into the vacuum chamber and mounted using a custom magnetic joint-based sample holder adapted from similar devices used in cryo­electron microscopy (Mykhaylyk & Wagner, 2013 ▸). X-ray tomography will be used to determine the dimensions of the crystal for empirical absorption corrections. The first data sets from the beamline are expected in early 2015.

Bottom Line: Today, native SAD sits on the verge of becoming a 'first-choice' method for both de novo and molecular-replacement structure determination.This article will focus on advances that have caught the attention of the community over the past five years.It will also highlight both de novo native SAD structures and recent structures that were key to methods development.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, University of Georgia , Athens, Georgia, USA.

ABSTRACT
Native SAD phasing uses the anomalous scattering signal of light atoms in the crystalline, native samples of macromolecules collected from single-wavelength X-ray diffraction experiments. These atoms include sodium, magnesium, phosphorus, sulfur, chlorine, potassium and calcium. Native SAD phasing is challenging and is critically dependent on the collection of accurate data. Over the past five years, advances in diffraction hardware, crystallographic software, data-collection methods and strategies, and the use of data statistics have been witnessed which allow 'highly accurate data' to be routinely collected. Today, native SAD sits on the verge of becoming a 'first-choice' method for both de novo and molecular-replacement structure determination. This article will focus on advances that have caught the attention of the community over the past five years. It will also highlight both de novo native SAD structures and recent structures that were key to methods development.

No MeSH data available.