A method for performing high-throughput in situ serial X-ray crystallography with soluble and membrane proteins in the lipid cubic phase at cryogenic temperatures (100 K) is described. It works with nanogram to single-digit microgram quantities of protein and lipid (and ligand when present), and is compatible with both high-resolution native data collection and experimental phasing without the need for crystal harvesting.

The application of the EIGER hybrid photon-counting pixel detector in macromolecular crystallography is presented. Data-collection strategies exploiting the unique features of EIGER are discussed.

Pentaindenocorannulene (C H , 1), a deep bowl polynuclear aromatic hydrocarbon, accepts 4 electrons, crystallizes in columnar bowl-in-bowl assemblies and forms a nested C @1 complex. Spectra, structures and computations are presented.

As a protective envelope surrounding the bacterial cell, the peptidoglycan sacculus is a site of vulnerability and an antibiotic target. Peptidoglycan components, assembled in the cytoplasm, are shuttled across the membrane in a cycle that uses undecaprenyl-phosphate. A product of peptidoglycan synthesis, undecaprenyl-pyrophosphate, is converted to undecaprenyl-phosphate for reuse in the cycle by the membrane integral pyrophosphatase, BacA. To understand how BacA functions, we determine its crystal structure at 2.6 Å resolution. The enzyme is open to the periplasm and to the periplasmic leaflet via a pocket that extends into the membrane. Conserved residues map to the pocket where pyrophosphorolysis occurs. BacA incorporates an interdigitated inverted topology repeat, a topology type thus far only reported in transporters and channels. This unique topology raises issues regarding the ancestry of BacA, the possibility that BacA has alternate active sites on either side of the membrane and its possible function as a flippase.

De novo membrane protein structure determination is often limited by the availability of large crystals and the difficulties in obtaining accurate diffraction data for experimental phasing. Here we present a method that combines in situ serial crystallography with de novo phasing for fast, efficient membrane protein structure determination. The method enables systematic diffraction screening and rapid data collection from hundreds of microcrystals in in meso crystallization wells without the need for direct crystal harvesting. The requisite data quality for experimental phasing is achieved by accumulating diffraction signals from isomorphous crystals identified post-data collection. The method works in all experimental phasing scenarios and is particularly attractive with fragile, weakly diffracting microcrystals. The automated serial data collection approach can be readily adopted at most microfocus macromolecular crystallography beamlines.