p321

P321 is probably my favourite crystallographic spacegroup, as viral fibre proteins also seem to like to crystallise "in it".

The name may be seen as a blatant almost-copy of the much more professional protein crystallography blog www.p212121.com and it perhaps is. In any case, this is going to be much more low-key and probably have much more infrequent entries...

Crystallography dead and buried? I think not!

For those who think crystallography is dead and buried, the issue of Nature of 19/3/2009 has three (interesting!) papers with X-ray crystallography results.

On page 305 Koder et al. describe the design and engineering of an O2 transport proteins, mimicking haemoglobin in many aspects. The design was guided by structure determination through NMR spectroscopy and X-ray crystallography. Although their protein was small enough to be studied by NMR (which has the advantage of not having to crystallise the protein and of being able to study dynamic properties of proteins in solution), they still chose to also determine several structures by crystallography. Probably because it provides an even more accurate view...

On page 315, Lee et al. have produced hybrid organic-inorganic rotaxanes and molecular shuttles - and managed to crystallise and solve the structures of these dynamic molecules.

Finally, on page 367, Hearn et al. present studies of a bacterial membrane transport protein that transports hydrophobic compounds. They show, via mutational and structural analyses, that the compounds leave the transporter through a "side door", into the membrane. Presumably, they then access the periplasmic space by diffusion. As membrane proteins are impossible (or at least very difficult) to study at high resolution by any other technique, X-ray crystallography was the method of choice here.

My conclusion for today, X-ray crystallography is alive and well and has provided essential information for three important papers. What IS clearly a trend, is that high-impact papers contains structural information more and more as a part, not as the main "show" like before.