The influence of an internal electric field upon protein crystallization using the gel-acupuncture method

The influence of an internal electric field upon the protein structure of crystals grown inside capillary tubes is evaluated during the crystallization process by means of the gel-acupuncture method using lysozyme and thaumatin.

Structure of pteridine reductase (PTR1) from Leishmania tarentolae

The crystal structure of PTR1 from L. tarentolae as a binary complex with NADPH at 2.8 Å resolution has been solved by molecular-replacement techniques using the recently reported L. major PTR1 structure as a search model.

Auracyanin B structure in space group P6₅

A new crystal form of auracyanin B, a `blue' copper protein from the thermophilic green photosynthetic bacterium C. aurantiacus, has been refined at 1.9 Å resolution.

Structure of the phenylhydrazine adduct of the quinohemoprotein amine de­hydrogenase from Paracoccus denitrificans at 1.7 Å resolution

The binding site for phenylhydrazine in the quinohemoprotein amine dehydrogenase has been identified as the C6 position of the redox cofactor cysteine tryptophylquinone. This result firmly establishes C6 as the site of Schiff-base formation during catalytic turnover of this enzyme.

Estimation of weights and validation: a marginal likelihood approach

An estimator of weights for restrained macromolecular refinement is proposed which is based on an approximation of a marginal likelihood function of the weighting parameters and which uses all the X-ray data.

Structural studies of hydrogen bonds in the high-affinity streptavidin–biotin complex: mutations of amino acids interacting with the ureido oxygen of biotin

Mutation of residues in streptavidin capable of hydrogen bonding to biotin causes significant changes in the binding constants for this protein/ligand system. Structure analyses show few changes in the three-dimensional structures of biotin complexes with the mutated proteins.

Structure of a king cobra phospholipase A₂ determined from a hemihedrally twinned crystal

The 2.1 Å resolution structure of a king cobra PLA₂ was determined by molecular replacement from a perfectly hemihedrally twinned crystal and compared with the structure of a homologous PLA₂ from the same venom.

Structure of Rhodoferax fermentans high-potential iron–sulfur protein solved by MAD

This paper describes the structure solution and the resultant model of R. fermentans HiPIP, a bacterial iron–sulfur protein with high reduction potential.

Monoclinic guanidino­acetate methyltransferase and gadolinium ion-binding characteristics

A crystal structure of guanidinoacetate methyltransferase in a monoclinic modification was determined in which three of four subunits have a catalytically unfavorable loop containing Tyr136. From analysis of the Gd ion-binding site, characteristic features of Gd-ion binding have been revealed and may be useful for preparing heavy-atom derivatives for phasing.

High-resolution structure of phenol hydroxylase and correction of sequence errors

New diffraction data for phenol hydroxylase have been collected. Refinement to 1.7 Å resolution resulted in a final free R factor of 18.0%. The model was also corrected for 11 earlier sequencing errors.

Analysis of three crystal structure determinations of a 5-methyl-6-N-methylanilino pyrido­pyrimidine antifolate complex with human di­hydrofolate reductase

Structural data are reported for the first example of the potent antifolate inhibitor 2,4-diamino-5-methyl-6-[(3′,4′,5′-trimethoxy-N-methylanilino)methyl]pyrido[2,3-d]pyrimidine (1) in complex with human dihydrofolate reductase (hDHFR) and NADPH.

Structure of Thermus thermophilus HB8 H-protein of the glycine-cleavage system, resolved by a six-dimensional molecular-replacement method

Because of the large number of molecules within a closely packed unit cell, this structure was solved by six-dimensional molecular replacement. Comparison with its counterpart from pea reveals highly conserved regions that are likely to be involved in intermolecular interactions.

Automatic classification of sub-microlitre protein-crystallization trials in 1536-well plates

A technique for automatically evaluating microbatch (sub-microlitre drop) protein crystallization trials is described.

Structural genomics of the SARS coronavirus: cloning, expression, crystallization and preliminary crystallographic study of the Nsp9 protein

A SARS-CoV whole-genome approach has been developed aimed at determining the crystal structure of all of its proteins or domains. Here, the cloning, E. coli expression, purification, and crystallization of the SARS-CoV Nsp9 protein, the first SARS-CoV protein to be crystallized, are reported.

Crystallization of the chaperonin GroEL–GroES complex from Thermus thermophilus HB8

The native GroEL-GroES complex was isolated from T. thermophilus HB8 and crystallized. The triclinic crystal diffracted to 3.0 Å resolution.

Crystallization and preliminary crystallographic study of rBmKαIT1, a recombinant α-insect toxin from the scorpion Buthus martensii Karsch

An α-insect toxin from the scorpion B. martensii Karsch has been expressed, purified and crystallized.

Crystallization and preliminary X-ray diffraction studies of aclacinomycin-10-methyl esterase and aclacinomycin-10-hydroxylase from Streptomyces purpurascens

Crystals suitable for structure determination of two enzymes in the biosynthesis pathway of anthracyclines in Streptomyces, aclacinomycin-10-methyl esterase and aclacinomycin-10-hydroxylase, have been grown.

Crystallization and preliminary X-ray crystallographic studies of phosphoenolpyruvate carboxykinase from Corynebacterium glutamicum

Phosphoenolpyruvate carboxykinase (PCK) is a key enzyme involved in the regulation of gluconeogenesis. C. glutamicum PCK has been crystallized and X-ray diffraction data have been collected to 2.8 Å resolution.

Purification, crystallization and preliminary X-ray studies of ClpX from Helicobacter pylori

ClpX from H. pylori has been overexpressed, purified and crystallized. The crystals diffracted to 2.6 Å resolution.

Overproduction, crystallization and preliminary X-ray diffraction analysis of probable ATP sulfurylase from Thermus thermophilus HB8

A probable ATP sulfurylase from T. thermophilus HB8 was overexpressed in E. coli and crystallized in the presence of adenosine-5′-phosphosulfate.

Purification, crystallization and preliminary X-ray crystallographic analysis of nucleoside diphosphate kinase from rice

Crystals of nucleoside diphosphate kinase from rice have been obtained.

Cloning, expression, purification, crystallization and initial crystallographic analysis of the lysine-biosynthesis LysX protein from Thermus thermophilus HB8

LysX protein, involved in the lysine-biosynthesis pathway in T. thermophilus, was cloned, expressed, purified and crystallized. Complete diffraction data sets were collected for the two crystal forms at 2.5 and 3.1 Å resolution. Structure determination is now in progress.

Coenzyme F₄₂₀-dependent methylene­tetra­hydro­methanopterin de­hydrogenase from Methanopyrus kandleri: the selenome­thionine-labelled and non-labelled enzyme crystallized in two different forms

Methanogenic F₄₂₀-dependent methylene-H4MPT dehydrogenase has been expressed, purified and crystallized.  Crystals of selenomethionine-labelled enzyme diffracted to 1.5 Å resolution.

X-ray crystallographic characterization and phasing of an NtrC homologue

A two-domain construct of ZraR (HydG) response regulator from S. typhimurium has been crystallized and diffraction data have been recorded to 3.0 Å resolution.

Crystallization and preliminary X-ray studies of xylanase 10B from Thermotoga maritima

Hyperthermophilic xylanase 10B from T. maritima MSB8 has been crystallized. A complete diffraction data set was collected up to 2.5 Å resolution.

Crystallization and preliminary X-ray analysis of inorganic polyphosphate/ATP-glucomannokinase from Arthrobacter sp. strain KM

The crystallization of and preliminary X-ray data for inorganic polyphosphate [poly(P)]/ATP-glucomannokinase from Arthrobacter sp. strain KM are presented.

Purification, crystallization and preliminary diffraction studies of the Pseudomonas aeruginosa strain K122-4 monomeric pilin

The expression, purification, crystallization and preliminary X-ray diffraction studies of the monomeric pilin from P. aeruginosa strain K122-4 are reported.

Crystallization and preliminary X-ray diffraction studies on recombinant di­aminopropionate ammonia lyase from Escherichia coli

The PLP-dependent enzyme diaminopropionate ammonia lyase from E. coli has been crystallized in two forms. The monoclinic (P2₁) and the tetragonal (P4₁2₁2 or P4₃2₁2) forms diffracted X-rays to 2.5 and 3.0 Å resolution, respectively.

Preliminary X-ray characterization and phasing of a type II cohesin domain from the cellulosome of Acetivibrio cellulolyticus

Native and SeMet derivatives of a type II cohesin from the cellulosomal system of A. cellulolyticus have been expressed, purified and crystallized in a trigonal form. Diffraction data were collected to 1.90 Å. In addition, orthorhombic crystals of the native protein were obtained that diffracted to 1.2 Å. Structures were solved using a combination of SIRAS and molecular replacement.

Crystallization and preliminary crystallographic studies of Escherichia coli CcmG/DsbE protein

E. coli CcmG/DsbE has been crystallized using the vapour-diffusion technique and X-ray data have been collected to 1.9 Å resolution.

Structure and oligomeric state of the mammalian tumour-associated antigen UK114

The crystal structure of UK114 has been determined, revealing a trimeric arrangement. It was confirmed by ultracentrifugation studies that UK114 is also a trimer in solution.