Showing papers by "Chantal Abergel published in 2000"

Crystallization and preliminary crystallographic study of b0220, an 'ORFan' protein of unknown function from Escherichia coli.

Abstract: Newly sequenced microbial genomes continue to reveal up to 50% functionally uncharacterized `anonymous' genes. A significant fraction of these anonymous ORFs does not exhibit any sequence similarity to any protein in the databases and constitutes a set of unique sequences, denoted `ORFans'. The structure determination of ORFan proteins is both of evolutionary and functional interest. Here, the first crystallization of an Escherichia coli ORFan gene product, the 157 amino-acid b0220 protein, is reported. The crystals belong to the trigonal space group P3 or P31, with unit-cell parameters a = b = 47.2, c = 88.4 A. There are two molecules in the asymetric unit. Frozen crystals diffract to 1.6 A resolution using synchrotron radiation. Phasing was performed using multiwavelength anomalous dispersion (MAD) on the selenomethionine-substituted b0220 protein.

Crystallization and preliminary crystallographic study of an extremophile cytochrome c4 from Thiobacillus ferrooxidans.

Abstract: Soluble periplasmic dihaemic cytochrome c4, of 21 293 Da molecular mass, has been characterized from Thiobacillus ferrooxidans, an acidophilic bacteria. The native cytochrome has been purified from the bacteria using ion-exchange chromatography and crystallized using solution 27 of the Hampton Research Crystal Screen II. The crystals belong to the hexagonal space group P6222 or P6422, with unit-cell parameters a = 101.59, b = 101.59, c = 151.59 A. Frozen crystals diffract to 2.17 A resolution. The MAD method is currently being used (four Fe atoms per asymmetric unit) to solve the protein structure.