Biological Crystallography

 

Acta Cryst. (2007). D63, 751-758  [ doi:10.1107/S0907444907025620 ]

What happens when the signs of anomalous differences or the handedness of substructure are inverted?

J. Wang, A. Wlodawer and Z. Dauter

Synopsis: The relationships between phases and electron-density maps obtained with correctly or wrongly interpreted anomalous differences or handedness of substructure are discussed.

Online 15 June 2007

 

Acta Cryst. (2007). D63, 759-768  [ doi:10.1107/S0907444907019580 ]

Using X-ray absorption spectra to monitor specific radiation damage to anomalously scattering atoms in macromolecular crystallography

V. Oliéric, E. Ennifar, A. Meents, M. Fleurant, C. Besnard, P. Pattison, M. Schiltz, C. Schulze-Briese and P. Dumas

Synopsis: It is shown that two major causes of `white-line' variation at the bromine K-absorption edge are, first, the dose-dependent cleavage of C-Br bonds and, second, the crystal orientation versus the beam polarization. The former effect allows monitoring the cleavage of anomalously scattering atoms during data collection, which is important for the RIP method.

Online 15 June 2007

 

Acta Cryst. (2007). D63, 769-779  [ doi:10.1107/S0907444907019725 ]

Structure of the small GTPase Rab27b shows an unexpected swapped dimer

L. M. G. Chavas, S. Torii, H. Kamikubo, M. Kawasaki, K. Ihara, R. Kato, M. Kataoka, T. Izumi and S. Wakatsuki

Synopsis: The crystal structures of dimeric Rab27b-GDP in three different space groups exhibit an atypical domain swapping of the switch and interswitch regions.

PDB references: 2iey, 2iez and 2if0

Online 15 June 2007

 

Acta Cryst. (2007). D63, 780-792  [ doi:10.1107/S0907444907021981 ]

Bence Jones KWR protein structures determined by X-ray crystallography

D. L. Makino, A. H. Henschen-Edman, S. B. Larson and A. McPherson

Synopsis: Bence Jones KWR protein, an immunoglobulin light-chain dimer, was crystallized under a variety of conditions after 40 y storage. Structures were obtained with packing arrangements consistent with biochemical and biophysical observations suggestive of an AL-type amyloid-fibril structure. Obtaining molecular-replacement solutions for these crystals proved to be a crystallographic challenge, probably owing to intradomain flexibility and the presence of disordered and proteolytically modified regions.

PDB references: 2omb, 2old and 2omn

Online 15 June 2007

 

Acta Cryst. (2007). D63, 793-799  [ doi:10.1107/S0907444907023451 ]

OASIS and molecular-replacement model completion

Y. He, D.-Q. Yao, Y.-X. Gu, Z.-J. Lin, C.-D. Zheng and H.-F. Fan

Synopsis: The application of dual-space fragment extension in the absence of SAD/SIR information makes the technique a general purpose tool for model completion, enabling the combination of direct-method phase refinement with the molecular-replacement technique.

Online 15 June 2007

 

Acta Cryst. (2007). D63, 800-811  [ doi:10.1107/S0907444907024353 ]

Structure and stability of designed TPR protein superhelices: unusual crystal packing and implications for natural TPR proteins

T. Kajander, A. L. Cortajarena, S. Mochrie and L. Regan

Synopsis: The structure and stability of consensus TPR proteins with eight and 20 repeats and their unusual crystallographic packing resulting from intramolecular symmetry are presented.

PDB references: 2f07, 2avp and 2hyz

Online 15 June 2007

 

Acta Cryst. (2007). D63, 812-825  [ doi:10.1107/S090744490702464X ]

A posteriori design of crystal contacts to improve the X-ray diffraction properties of a small RNA enzyme

C. MacElrevey, R. C. Spitale, J. Krucinska and J. E. Wedekind

Synopsis: Insertion of a dangling 5'-uracil and incorporation of synthetic linkers at the domain interface of a minimal hairpin ribozyme have been investigated as means of favorably influencing crystal packing. These modifications lead to changes in the ribozyme's structural elements that mimic packing within a natural four-way helical junction, thereby providing an example of how knowledge-based design can be used to enhance the diffraction properties of a tertiarily folded RNA.

PDB references: 2npy, 2npz and 2oue

Online 15 June 2007

 

Acta Cryst. (2007). D63, 826-832  [ doi:10.1107/S0907444907025784 ]

Initial evaluations of the reproducibility of vapor-diffusion crystallization

J. Newman, J. Xu and M. C. Willis

Synopsis: Crystallization of lysozyme solutions reveals that even this robust protein shows very a significant variation in the reproducibility of crystal formation.

Online 15 June 2007

 

Acta Cryst. (2007). D63, 833-843  [ doi:10.1107/S0907444907026303 ]

High-resolution structures of oxidized and reduced thioredoxin reductase from Helicobacter pylori

T. N. Gustafsson, T. Sandalova, J. Lu, A. Holmgren and G. Schneider

Synopsis: The crystal structures of thioredoxin reductase from the gastric pathogen H. pylori in complex with NADP⁺ have been determined for the oxidized and reduced form of the enzyme at 1.7 and 1.45 Å resolution, respectively.

PDB references: 2q0l and 2q0k

Online 15 June 2007