1obu: Difference between revisions

[[Image:1obu.gif|left|200px]]<br /><applet load="1obu" size="350" color="white" frame="true" align="right" spinBox="true"  

Models of apocrustacyanin C(1) were refined against X-ray data recorded on Bending Magnet 14 at the ESRF to resolutions of 1.85 and 2 A from a space-grown and an earth-grown crystal, respectively, both using vapour-diffusion crystal-growth geometry. The space crystals were grown in the APCF on the NASA Space Shuttle. The microgravity crystal growth showed a cyclic nature attributed to Marangoni convection, thus reducing the benefits of the microgravity environment, as reported previously [Chayen et al. (1996), Q. Rev. Biophys. 29, 227-278]. A subsequent mosaicity evaluation, also reported previously, showed only a partial improvement in the space-grown crystals over the earth-grown crystals [Snell et al. (1997), Acta Cryst. D53, 231-239], contrary to the case for lysozyme crystals grown in space with liquid-liquid diffusion, i.e. without any major motion during growth [Snell et al. (1995), Acta Cryst. D52, 1099-1102]. In this paper, apocrustacyanin C(1) electron-density maps from the two refined models are now compared. It is concluded that the electron-density maps of the protein and the bound waters are found to be better overall for the structures of apocrustacyanin C(1) studied from the space-grown crystal compared with those from the earth-grown crystal, even though both crystals were grown using vapour-diffusion crystal-growth geometry. The improved residues are on the surface of the protein, with two involved in or nearby crystal lattice-forming interactions, thus linking an improved crystal-growth mechanism to the molecular level. The structural comparison procedures developed should themselves be valuable for evaluating crystal-growth procedures in the future.

1OBU is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homarus_gammarus Homarus gammarus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1OBU OCA].  

[[Category: Boggon, T J.]]

[[Category: Chayen, N E.]]

[[Category: Helliwell, J R.]]

[[Category: Zagalsky, P F.]]

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