Gd-HPDO3A, a complex to obtain high-phasing-power heavy-atom derivatives for SAD and MAD experiments: results with tetragonal hen egg-white lysozyme

A neutral gadolinium complex, Gd-HPDO3A, is shown to be a good candidate to obtain heavy-atom derivatives and solve macromolecular structures using anomalous dispersion. Tetragonal crystals of a gadolinium derivative of hen egg-white lysozyme were obtained by co-crystallization using different concentrations of the complex. Diffraction data from three derivative crystals were collected to a resolution of 1.7 Å using Cu Kα radiation from a rotating anode.

Structural flexibility, an essential component of the allosteric activation in Escherichia coli glucosamine-6-phosphate deaminase

A new crystallographic structure of the free active-site R conformer of the allosteric enzyme glucosamine-6-phosphate deaminase from Escherichia coli, coupled with previously reported structures of the T and R conformers, generates a detailed description of the heterotropic allosteric transition in which structural flexibility plays a central role.

De novo phasing of two crystal forms of tryparedoxin II using the anomalous scattering from S atoms: a combination of small signal and medium resolution reveals this to be a general tool for solving protein crystal structures

The structures of two crystal forms of tryparedoxin II from C. fasciculata have been determined de novo by exploiting the anomalous scattering at 1.77 Å wavelength of the S atoms in the native protein.

The 2.6 Å resolution structure of Rhodobacter capsulatus bacterioferritin with metal-free dinuclear site and heme iron in a crystallographic `special position'

The first structure of a bacterioferritin from a photosynthetic organism (R. capsulatus) was solved by the MIR method at 2.6 Å resolution in the I422 space group and compared with that from E. coli solved in the P2₁ and P4₂2₁2 space groups. The new crystals reveal for the first time the presence of the non-symmetric heme molecule on a twofold crystallographic axis. It is concluded that in the crystal each heme site contains a symmetrical mixture of heme in two orientations.

The X-ray crystal structure of P3, the major coat protein of the lipid-containing bacteriophage PRD1, at 1.65 Å resolution

P3 is a trimer of double viral jelly rolls and so has an architecture similar to hexon, its counterpart in the mammalian adenovirus. The X-ray structure at 1.65 Å resolution shows flexible loops at locations important for capsid interactions and an intricate water network that appears to contribute additional stability to the `trimerization loops' at the top of the molecule.

Low-resolution detergent tracing in protein crystals using xenon or krypton to enhance X-ray contrast

The use of xenon and krypton as hydrophobic probes to distinguish between aqueous and detergent solvent regions in crystals of the membrane protein OmpF porin by conventional X-ray crystallography is assessed.

The crystal and molecular structures of diferric porcine and rabbit serum transferrins at resolutions of 2.15 and 2.60 Å, respectively

The X-ray structures of rabbit and porcine serum transferrins are reported at resolutions of 2.6 and 2.15 Å, respectively. The more acid-labile release of iron from serum transferrins than from lactoferrins is discussed.

X-ray structure of nitric oxide reductase (cytochrome P450nor) at atomic resolution

Crystal structures of the nitric oxide reductase cytochrome P450nor in the ferric resting and the ferrous carbonmonoxy (CO) states have been determined at 1.00 and 1.05 Å resolution, respectively.

Sine-enhanced Shake-and-Bake: the theoretical basis and applications to Se-atom substructures

The sine-enhanced minimal function and the corresponding sine-enhanced Shake-and-Bake procedure have been proposed and tested. With proper choice of parameter values, the sine-enhanced Shate-and-Bake procedure outperformed the traditional Shake-and-Bake by a two- to eightfold increase in success rate for Se-atom substructures.

Generation of noble-gas binding sites for crystallographic phasing using site-directed mutagenesis

A novel approach for de novo phase determination using site-directed mutagenesis to generate noble-gas binding sites in proteins is described. MIR phases from xenon derivatives obtained using this method compare favorably with MAD phases from selenomethionine substitution.

Structure of an acidic phospholipase A₂ from the venom of Deinagkistrodon acutus

The structure of an acidic PLA₂ from D. acutus been determined by molecular replacement with significant conformational differences observed in segment 14–23 of the two molecules in the asymmetric unit. This segment is related to the interface recognition site.

A branched N-linked glycan at atomic resolution in the 1.12 Å structure of rhamnogalacturonan acetylesterase

The structure of the glycoprotein rhamnogalacturonan acetylesterase has been refined at 1.12 Å resolution. The branched N-linked glycan structure has been refined without target values for bond lengths and angles and the resulting values are compared with the current dictionary values obtained from small-molecule studies.

Crystallization of the Zα domain of the human editing enzyme ADAR1 complexed with a DNA–­RNA chimeric oligonucleotide in the left-handed Z-conformation

The Zα domain of human ADAR1 has been cocrystallized with the chimeric oligonucleotide (dCrG)₃ in the Z-conformation.

Crystallization and preliminary X-ray crystallographic studies of a mutant of ribosome recycling factor from Escherichia coli, Arg132Gly

Ribosome recycling factor from E. coli has been crystallized in space group P2₁ with no additives. Data were collected to 2.2 Å and molecular replacement gave solutions for the rotation and translation functions.

Crystallization and preliminary crystallographic analysis of a metastasis-inducing protein, human S100A4

SeMet S100A4 (human) has been crystallized using similar conditions to those used for the native protein. SeMet S100A4 crystals diffract better than the native for data collection and belong to space group P6 or P3.

Crystallization and preliminary crystallographic studies of five crystal forms of Escherichia coli L-asparaginase II (Asp90Glu mutant)

E. coli L-asparaginase II with a Asp90Glu mutation in the active site has been crystallized in five polymorphic forms.

Purification, crystallization and preliminary X-ray diffraction analysis of human phosphoserine phosphatase

Phosphoserine phosphatase, a human enzyme involved in the L-serine biosynthesis pathway, has been purified and crystals suitable for structural analysis have been obtained.

Expression, crystallization and preliminary X-ray analysis of human and rabbit 20α-hydroxysteroid de­hydrogenases in complex with NADP(H) and various steroid substrates

The human and rabbit 20α-hydroxysteroid dehydrogenases, which catalyse the inactivation of progesterone, have been expressed in E. coli, purified and subsequently crystallized. Several crystal complexes have been obtained and three of them diffract to better than 2.0 Å resolution.

Crystallization and preliminary X-ray analysis of human nicotinamide mononucleotide adenylyltransferase (NMNAT)

The human form of nicotinamide mononucleotide adenylyltransferase which catalyses the final step in the synthesis of nicotinamide-adenine dinucleotide (NAD⁺) by transferring the adenylyl moiety of ATP to nicotinamide mononucleotide with the release of pyrophosphate has been crystallized in the presence of NAD⁺.

Crystallization and preliminary crystallographic study of an invertebrate C-type lectin, CEL-I, from the marine invertebrate Cucumaria echinata

An invertebrate C-type lectin, CEL-I, from the marine invertebrate C. echinata was crystallized and 2.0 Å resolution data were collected using synchrotron radiation.

Crystallization and preliminary crystallographic studies of dimeric disintegrins from the venom of two Agkistrodon snakes

Two dimeric disintegrins named PVS and acostatin were crystallized and data were collected to 2.0 and 2.8 Å resolution, respectively.

Crystallization of scytalone dehydratase F162A mutant in the unligated state and a preliminary X-ray diffraction study at 37 K

Scytalone dehydratase Phe162Ala variant is a good target for investigating the substrate-binding mechanism of the enzyme. the variant enzyme was crystallized in its unligated state, and the diffraction data of the crystal were collected at 37 K using synchrotron X-rays.

Crystallization of a large single crystal of a B-DNA decamer for a neutron diffraction experiment by the phase-diagram technique

Crystallization of a large single crystal of a B-DNA decamer, d(CCATTAATGG), for a neutron-diffraction experiment has been accomplished by an analysis of its solubility phase diagram and a large single crystal was successfully crystallized at around the minimum solubility point of the oligonucleotide.

Cloning, expression and preliminary X-ray analysis of the di­hydroorotase from the hyperthermophilic eubacterium Aquifex aeolicus

Dihydroorotase from the extreme hyperthermophile A. aeolicus was cloned and expressed at high levels in E. coli. Crystals of the purified wild type and selelnomethionine-substituted enzyme, space group C2, diffracted to a resolution of 1.7 Å.

Crystallization and preliminary X-ray diffraction studies of catalase–peroxidase from Synechococcus PCC 7942

Catalase–peroxidase from Synechococcus PCC 7942 has been purified and crystallized in the tetragonal space group P4₁2₁2 or P4₃2₂1. A native data set has been collected to 2.3 Å resolution using the SPring-8 synchrotron-radiation source.

Purification and crystallization of the respiratory complex formate de­hydrogenase-N from Escherichia coli

A membrane-protein complex, formate dehydrogenase-N from E. coli, has been purified and crystallized.

Crystallization and preliminary X-ray diffraction analysis of monkey dimeric di­hydrodiol de­hydrogenase

Hexagonal crystals of dimeric dihydrodiol dehydrogenase from monkey were grown from buffered ammonium phosphate solutions. This is the first crystallization report of a dimeric dihydrodiol dehydrogenase.

Crystallization and preliminary crystallographic analysis of the soluble α-glycerophosphate oxidase from Streptococcus sp.

The crystallization of soluble FAD-dependent α-glycerophosphate oxidase from Streptococcus sp. is reported. Synchrotron X-ray radiation was used to collect diffraction data to 2.4 Å resolution.

Crystallization and preliminary X-ray diffraction analysis of the seed lectin from Parkia platycephala

Crystallization and preliminary X-ray diffraction analysis of P. platycephala lectin, a Mimosoideae regarded as the most primitive group of Leguminosae plants, are reported. Resolution of this structure will show the arrangement of three tandem beta-prism domains, a novel architecture for a leguminous lectin.

Crystallization and preliminary X-ray studies of the protease domain of the heat-shock protein HtrA from Thermotoga maritima

The protease domain of T. maritima HtrA has been purified and crystallized. The crystals diffracted to 2.7 Å resolution.

Crystallization and preliminary X-ray crystallographic studies of a macromolecular antitumour antibiotic, C1027

C1027 is a macromolecular antitumour antibiotic produced by Streptomyces globispourus C1027 and consists of an apoprotein and a non-protein labile chromophore. The purified C1027 was monodisperse according to dynamic light-scattering measurements and crystallized in two different crystal forms from two different starting conditions using the vapour-diffusion method.

Crystallization and preliminary X-ray analysis of an enantioselective halohydrin dehalogenase from Agrobacterium radiobacter AD1

Halohydrin dehalogenases are key enzymes in the bacterial degradation of vicinal halopropanols and structurally related nematocides. The enantioselective halohydrin dehalogenase HheC from A. radiobacter AD1 was crystallized and data were collected to 3.0 Å resolution.

Expression, purification, crystallization and preliminary X-ray analysis of the acyl carrier protein synthase (acpS) from Mycobacterium tuberculosis

Acyl carrier protein synthase (acpS) catalyzes the formation of holo-ACP, which mediates the transfer of acyl fatty-acid intermediates during the biosynthesis of fatty acids and lipids. The M. tuberculosis enzyme has been expressed and purified, and then crystallized by the vapour-diffusion method using 2-propanol as a precipitant.

Expression, purification, crystallization and preliminary crystallographic analysis of a thermostable lipase from Bacillus stearothermophilus P1

A thermostable lipase from B. stearothermophilus P1 has been overexpressed, purified and crystallized.

Crystallization and preliminary crystallographic investigation of a low-pH native insulin monomer with flexible behaviour

Porcine insulin has been crystallized as a monomer in the presence of 20% acetic acid. X-ray data has been collected to 1.6 Å resolution.

The X-ray structure of a recombinant major urinary protein at 1.75 Å resolution. A comparative study of X-ray and NMR-derived structures. Addendum

Addendum to Acta Cryst. (2001), D57, 1863–1869.

Notes for authors