Diffraction structural biology – introductory overview

An introductory overview to the special issue papers on diffraction structural biology in this issue of the journal.

Three-dimensional structural analysis of eukaryotic flagella/cilia by electron cryo-tomography

Based on the molecular architecture revealed by electron cryo-tomography, the mechanism of the bending motion of eukaryotic flagella/cilia is discussed.

Crystal structure of stable protein CutA1 from psychrotrophic bacterium Shewanella sp. SIB1

The crystal structure of CutA1 from the psychrotrophic bacterium Shewanella sp. SIB1 in a trimeric form was determined at 2.7 Å resolution. This is the first crystal structure of a psychrotrophic CutA1.

UV LED lighting for automated crystal centring

A low-cost light-emitting diode (LED) UV source has been developed for facilitating macromolecular sample centring in the X-ray beam.

Approach for growth of high-quality and large protein crystals

Three crystallization methods, including crystallization in the presence of a semi-solid agarose gel, top-seeded solution growth (TSSG) and a large-scale hanging-drop method, have previously been presented. In this study, crystallization has been further evaluated in the presence of a semi-solid agarose gel by crystallizing additional proteins. A novel crystallization method combining TSSG and the large-scale hanging-drop method has also been developed.

The alternating access mechanism of transport as observed in the sodium-hydantoin transporter Mhp1

Crystal structures of a membrane protein transporter in three different conformational states provide insights into the transport mechanism.

Crystallization and preliminary structural analysis of the giant haemoglobin from Glossoscolex paulistus at 3.2 Å

Diffraction data to 3.2 Å from crystals of the 3.6 MDa erythrocruorin from a Brazilian earthworm represent the highest resolution reported to date for similar complexes. An unambiguous molecular replacement solution shows the particle to belong to the type I class.

Structure analysis of group I plant nucleases

Structural properties of plant nuclease TBN1 are studied using synchrotron radiation to explain its specificity, role of glycosylation and to contribute to potential application in cancer treatment.

A new paradigm for macromolecular crystallography beamlines derived from high-pressure methodology and results

Macromolecular crystallography at high pressure (HPMX) is a mature technique. Shorter X-ray wavelengths increase data collection efficiency on cryocooled crystals. Extending applications and exploiting spin-off of HPMX will require dedicated synchrotron radiation beamlines based on a new paradigm.

Single-crystal Raman spectroscopy and X-ray crystallography at beamline X26-C of the NSLS

The collection of absorption and Raman spectroscopic data correlated with X-ray diffraction data allows investigators to understand the atomic structure as well as the electronic and vibrational characteristics of their samples, to identify transiently formed intermediates and to explore mechanistic questions. Raman spectroscopy instrumentation at beamline X26-C at the NSLS is currently available to the general user population.

Biomolecular solution X-ray scattering at the National Synchrotron Light Source

A new beamline for simultaneous SAXS/WAXS of biomolecules in solution is described.

Structural insights and ab initio sequencing within the DING proteins family

DING proteins constitute a recently discovered protein family that is ubiquitous in eukaryotes. The structural insights and the physiological involvements of these intriguing proteins are hereby deciphered.

Protein surface shielding agents in protein crystallization

The crystallization process can be controlled by protein surface shielding agents blocking undesirable competitive adhesion modes during non-equilibrium processes of deposition of protein molecules on the surface of growing crystalline blocks. The hypothesis is based on a number of experimental proofs from diffraction experiments and also retrieved from the Protein Data Bank.

Research and development of an electron beam focusing system for a high-brightness X-ray generator

In order to minimize the size of the X-ray source for a U-shaped rotating anticathode X-ray generator, the electron beam is focused over a short distance by a combined-function bending magnet. Simulation predicts that the beam brightness will reach almost 500 kW mm⁻² for a 120 keV/75 mA beam.

Detection of the reaction intermediates catalyzed by a copper amine oxidase

Consecutive temporal analyses of enzyme structure have been performed during reactions in order to clarify the structure-based reaction mechanism. Four intermediate structures have been determined.

Purine nucleoside phosphorylase from Schistosoma mansoni in complex with ribose-1-phosphate

A binary complex between a low-molecular-weight purine nucleoside phosphorylase and ribose-1-phosphate is described for the first time and comparisons with known ternary complexes are drawn.

Structure of the inhibitor complex of old yellow enzyme from Trypanosoma cruzi

The structures of old yellow enzyme from Trypanosoma cruzi which produces prostaglandin F_2α from PGH₂ have been determined in the presence or absence of menadione.

Microcrystallography, high-pressure cryocooling and BioSAXS at MacCHESS

Three research initiatives pursued by the Macromolecular Diffraction Facility at the Cornell High Energy Synchrotron Source (MacCHESS) are presented.

Using lanthanoid complexes to phase large macromolecular assemblies

A lanthanoid complex, [Eu(DPA)₃]³⁻, was used to obtain experimental phases at 4.0 Å resolution of PhTET1-12s, a large self-compartmentalized homo-dodecameric protease complex of 444 kDa.

Deriving the ultrastructure of α-crustacyanin using lower-resolution structural and biophysical methods

The structure of α-crustacyanin has been determined to 30 Å resolution using negative-stain electron microscopy (EM) single-particle averaging and modelling with the β-crustacyanin dimer from the crystal structure (Protein Data Bank code 1gka), guided by PISA protein subunit interface calculations for 1gka, and compared with the protein arrangements observed in the crystal lattice of 1gka. This α-crustacyanin EM model has been checked against SAXS experimental data, including comparison with rigid-body models calculated from the SAXS data, and finally with analytical ultracentrifugation measurements.

Optimization of salt concentration in PEG-based crystallization solutions

Optimal salt concentration in a PEG-based crystallization solution is important for successful crystal growth and can be predicted prior to performing crystallization experiments.

Improvement in the quality of hematopoietic prostaglandin D synthase crystals in a microgravity environment

Crystals of hematopoietic prostaglandin D synthase grown in microgravity show improved quality.

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Notes for authors 2011