Editorial.

The structure factors deposited with PDB entry 3k78 show properties inconsistent with experimentally observed diffraction data, and without uncertainty represent calculated structure factors. The refinement of the 3k78 model against these structure factors leads to an isomorphous structure different from the deposited model with an implausibly small R value (0.019).

A response to the article by Rupp (2012), Acta Cryst. F68, 366–376.

The structure of the third catalytic domain of the human protein disulfide isomerase ERp46 has been determined to 2.0 Å resolution.

Structural data for the ternary complex of P. carinii DHFR with NADPH and the potent inhibitor PY1014 reveal conformational changes that help to explain the weaker potency and selectivity of the pyrido[2,3-d]pyrimidine scaffold compared with the homologous pyrimidine series of antifolates.

Crystals of the SCAN domain of Zfp206 are tetragonal, belonging to space group I422 with unit-cell parameters a = 67.57, c = 87.54 Å and one molecule in the asymmetric unit, and diffract to 1.85 Å resolution.

AAC(6′)-Im is an N-acetyltransferase enzyme responsible for aminoglycoside resistance in E. faecium and E. coli isolates. Crystals of the kanamycin complex of this enzyme have been prepared and preliminary X-ray diffraction experiments have been undertaken.