This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Proteins are high-performance molecular machines that carry out nearly every biochemical function inside living cells. To understand how they achieve this, scientists often examine their detailed atomic structure, which holds important clues to their activity.
The more precision they achieve, the deeper the insight they may gain into the chemical principles that underlie protein structure and, ultimately, function. Marking a major advancement in X-ray crystallography, scientists led by Ashwin Chari from the Max Planck Institute for Multidisciplinary Sciences (Göttingen, Germany), Gleb Bourenkov from EMBL Hamburg (Hamburg, Germany), Clemens Schulze-Briese from DECTRIS (Baden, Switzerland), Paulina Maria Dominiak from the University of Warsaw (Poland) and Gérard Bricogne from Global Phasing Ltd. (Cambridge, UK) have determined the structure of the archaeal rubredoxin protein at a resolution of 0.43 Å. "This, to the best of our knowledge, represents the highest-resolution protein structure yet determined," Chari explained.
"This has been enabled by a series of technical innovations and streamlined procedures. We have combined cutting-edge X-ray crystallography with advanced quantum-chemical models, bridging the gap between structural biology and quantum chemistry." The results have now been published in Acta Crystallographica Section D: Structural Biology. Previous experiments by Chari, Bricogne and Bourenkov, also published in Acta Crystallographica Section D: Structural Biology, laid the groundwork for this resolution record.
There, the scientists investigated how X-rays alter protein structure and how radiation damage interferes with atomic model refinement and interpretation. During these experiments, the researchers developed a "resolution-in-dose" approach, which relied on low-dose data collection protocols on large protein crystals bathed in a "top-hat" beam, ultimately allowing the scientists to reach sub-Ångström resolutions. The new study made use of one of the world's brightest X-ray sources: PETRA III at DESY in Hamburg (Germany).
To collect the high-quality data that led to the resolution record, the scientists used the beamline P14 provided by EMBL Hamburg. This produces a tailored X-ray beam with a uniform radiation intensity, known as a "top-hat" beam. Its advantage: Its size and shape can be adjusted before the start of every data collection to match the dimensions of each protein crystal.
This allows precise control over the X-ray dose delivered to the sample—just as the "resolution-in-dose" approach suggests. The data collection and processing were carried out according to advanced protocols created on the fly by Global Phasing's workflow software, tailored to each individual sample and designed to produce high data quality. The high-resolution X-ray crystallographic data allowed the team to determine accurate nuclear positions of atoms within the structure, including all hydrogen atoms.
Extract — continue reading at the source.
