par Sainz, Germaine;Vicat, Jean;Kahn, Richard;Dideberg, O.;Tricot, Catherine 
;Stalon, Victor
Référence Acta crystallographica. Section D, Biological crystallography, 55, 9, page (1591-1593)
Publication Publié, 1999-09
;Stalon, Victor Référence Acta crystallographica. Section D, Biological crystallography, 55, 9, page (1591-1593)
Publication Publié, 1999-09
Article révisé par les pairs
| Résumé : | The catabolic ornithine carbamoyltransferase (OTCase) from Pseudomonas aeruginosa exhibits allosteric behaviour, with two conformational states of the molecule: an active R form and an inactive T form. The enzyme is a dodecamer with a molecular mass of 455700 Da. Three crystal forms have been obtained. Crystals of allosteric state T are rhombohedral, belonging to the R3 space group, with hexagonal unit-cell parameters a = b = 180.6, c = 122.0 Å. They diffract to a resolution of 4.5 Å. Two crystal forms for allosteric state R have been obtained, with hexagonal and cubic symmetries. Hexagonal crystals, which diffract to a resolution of 3.4 Å, belong to the space group P6 3 with unit-cell parameters a = b = 140.8, c = 145.6 Å. The cubic crystals belong to space group I23, with unit-cell parameter a = 134.32 Å and diffract to a resolution better than 2.5 Å. In all crystal forms, the dodecamer exhibits a 23 point-group symmetry. |
