workflow-tools-for-crystallographic-fragment-screening-at-helmholtz

Workflow and Tools for Crystallographic Fragment Screening at the Helmholtz-Zentrum Berlin

Fragment screening is a technique that helps to identify promising starting points for ligand design. Given that crystals of the target protein are ...

an-all-one-sample-holder-for-macromolecular-x-ray-crystallography

An All-in-one Sample Holder for Macromolecular X-ray Crystallography with Minimal Background Scattering

Macromolecular X-ray crystallography (MX) is the most prominent method to obtain high-resolution three-dimensional knowledge of biological macromolecules. ...

Helmholtz-Zentrum Berlin

The carbon cage of buckminsterfullerene I -C , which obeys the Isolated-Pentagon Rule (IPR), can be transformed to non-IPR cages in the course of high-temperature chlorination of C or C Cl with SbCl . The non-IPR chloro derivatives were isolated chromatographically (HPLC) and characterized crystallographically as  C Cl ,  C Cl , and  C Cl , which contain, respectively two, four, and four pairs of fused pentagons in the carbon cage. High-temperature trifluoromethylation of the chlorination products with CF I afforded a non-IPR CF derivative,  C (CF ) , which contains four pairs of fused pentagons in the carbon cage. Addition patterns of non-IPR chloro and CF derivatives were compared and discussed in terms of the formation of stabilizing local substructures on fullerene cages. A detailed scheme of the experimentally confirmed non-IPR C isomers obtained by Stone-Wales cage transformations is presented.

Fused-Pentagon Isomers of C Fullerene Isolated as Chloro and Trifluoromethyl Derivatives.

The crystal structure of the 268-residue periplasmic protein PA1624 from the opportunistic pathogen Pseudomonas aeruginosa PAO1 was determined to high resolution using the Se-SAD method for initial phasing. The protein was found to be monomeric and the structure consists of two domains, domains 1 and 2, comprising residues 24-184 and 185-268, respectively. The fold of these domains could not be predicted even using state-of-the-art prediction methods, and similarity searches revealed only a very distant homology to known structures, namely to Mog1p/PsbP-like and OmpA-like proteins for the N- and C-terminal domains, respectively. Since PA1624 is only present in an important human pathogen, its unique structure and periplasmic location render it a potential drug target. Consequently, the results presented here may open new avenues for the discovery and design of antibacterial drugs.

The hypothetical periplasmic protein PA1624 from Pseudomonas aeruginosa folds into a unique two-domain structure.

The unique crystallization properties of the antenna protein C-phycocyanin (C-PC) from the thermophilic cyanobacterium Thermosynechococcus elongatus are reported and discussed. C-PC crystallizes in hundreds of significantly different conditions within a broad pH range and in the presence of a wide variety of precipitants and additives. Remarkably, the crystal dimensions vary from a few micrometres, as used in serial crystallography, to several hundred micrometres, with a very diverse crystal morphology. More than 100 unique single-crystal X-ray diffraction data sets were collected from randomly selected crystals and analysed. The addition of small-molecule additives revealed three new crystal packings of C-PC, which are discussed in detail. The high propensity of this protein to crystallize, combined with its natural blue colour and its fluorescence characteristics, make it an excellent candidate as a superior and highly adaptable model system in crystallography. C-PC can be used in technical and methods development approaches for X-ray and neutron diffraction techniques, and as a system for comprehending the fundamental principles of protein crystallography.

ArticleTotal : 2	Year
Publication title Cited by 18	2021
Publication title Cited by 4	2019

Article	Year
Fused-Pentagon Isomers of C Fullerene Isolated as Chloro and Trifluoromethyl Derivatives. Chemistry (Weinheim an der Bergstrasse, Germany)\| PubMed ID: 31849115	2020
The hypothetical periplasmic protein PA1624 from Pseudomonas aeruginosa folds into a unique two-domain structure. Acta crystallographica. Section F, Structural biology communications\| PubMed ID: 33263573	2020
C-phycocyanin as a highly attractive model system in protein crystallography: unique crystallization properties and packing-diversity screening. Acta crystallographica. Section D, Structural biology\| PubMed ID: 33559611	2021

Christian G. Feiler

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