Introducing Methods Communications, a new category of contributions to Acta Crystallographica F

A new category of Acta Crystallographica F articles, Methods Communications, is introduced. The first of these to be published, describing an inexpensive crystallization imaging system, is discussed here. Readers are also reminded about another category of articles, Topical Reviews, which are now defined.

AMi: a GUI-based, open-source system for imaging samples in multi-well plates

Described here are instructions for building and using an inexpensive automated microscope that is driven by a dedicated graphical user interface. The system facilitates the automated imaging and manual inspection of multi-well plates.

The crystal structure of haemoglobin from Atlantic cod

The isolation of the dominant isoform of haemoglobin from Atlantic cod caught in southwest Norway is reported and its X-ray crystal structure is presented.

Crystal structure of the inhibitor-free form of the serine protease kallikrein-4

Kallikrein-4 (KLK4) is a serine protease that is an attractive target for prostate cancer therapeutics. Here, the first crystal structure of catalytically active KLK4 in an uninhibited state is reported. The 1.64 Å resolution structure shows a canonical fold, but uses a nonstandard rotamer in a specificity-determining residue. This model will prove useful in understanding the subtle structural changes that are induced upon the binding of a ligand, and thus in the future structure-guided design of KLK4 inhibitors.

Co-crystal structure of the iMango-III fluorescent RNA aptamer using an X-ray free-electron laser

The iMango-III aptamer demonstrates one of the largest fluorescence enhancements of all RNA aptamers. Here, the room-temperature crystal structure of the iMango-III aptamer determined using an X-ray free-electron laser is reported.

Crystal structure of the Schizosaccharomyces pombe U7BR E2-binding region in complex with Ubc7

A 1.7 Å resolution co-crystal structure of U7BR from Schizosaccharomyces pombe in complex with Ubc7 is reported. Structural comparisons and biochemistry suggest that U7BR presents a steric impediment to E1 binding and inhibits E1-mediated charging, respectively.

The Rel stringent factor from Thermus thermophilus: crystallization and X-ray analysis

Crystallization and structural analysis are reported of the Rel stringent factor from Thermus thermophilus in the resting state and bound to nucleotides.