Résumé
The archaebacterial-type asparagine synthetase A from Pyrococcus abyssi (AS-AR), which is related to asparaginyl-tRNA synthetase, was crystallized in two different conditions using the hanging-drop vapour-diffusion method. Crystals belonging to space group C2 with unit-cell parameters a = 103.6, b = 43.3, c = 121.5 A, beta = 112.6 degrees and one dimer per asymmetric unit were obtained in the presence of 2-propanol and PEG 4000 at pH 5.6. Another crystal form was obtained in the presence of dioxan and belongs to the monoclinic space group P2(1), with unit-cell parameters a = 96.8, b = 103.9, c = 98.4 A, beta = 107.5 degrees and two dimers per asymmetric unit. Two different native diffraction data sets were collected to 2.3 and 3.0 A resolution using synchrotron radiation and cryocooling for crystals belonging to space groups C2 and P2(1), respectively.