4lzt
|
ATOMIC RESOLUTION REFINEMENT OF TRICLINIC HEW LYSOZYME AT 295K
OverviewOverview
X-ray diffraction data have been collected at both low (120 K) and room, temperature from triclinic crystals of hen egg-white lysozyme to 0.925 and, 0.950 A resolution, respectively, using synchrotron radiation. Data from, one crystal were sufficient for the low-temperature study, whereas three, crystals were required at room temperature. Refinement was carried out, using the programs PROLSQ, ARP and SHELXL to give final conventional R, factors of 8.98 and 10.48% for data with F > 4sigma(F) for the low- and, room-temperature structures, respectively. The estimated r.m.s. coordinate, error is 0.032 A for protein atoms, 0.050 A for all atoms in the, low-temperature study, and 0.038 A for protein atoms and 0.049 A for all, atoms in the room-temperature case, as estimated from inversion of the, blocked least-squares matrix. The low-temperature study revealed that the, side chains of 24 amino acids had multiple conformations. A total of 250, waters, six nitrate ions and three acetate ions, two of which were, modelled with alternate orientations were located in the electron-density, maps. Three sections of the main chain were modelled in alternate, conformations. The room-temperature study produced a model with multiple, conformations for eight side chains and a total of 139 water molecules, six nitrate but no acetate ions. The occupancies of the water molecules, were refined in both structures and this step was shown to be meaningful, when assessed by use of the free R factor. A detailed description and, comparison of the structures is made with reference to the previously, reported structure refined at 2.0 A resolution.
About this StructureAbout this Structure
4LZT is a Single protein structure of sequence from Gallus gallus with NO3 as ligand. Active as Lysozyme, with EC number 3.2.1.17 Full crystallographic information is available from OCA.
ReferenceReference
Refinement of triclinic hen egg-white lysozyme at atomic resolution., Walsh MA, Schneider TR, Sieker LC, Dauter Z, Lamzin VS, Wilson KS, Acta Crystallogr D Biol Crystallogr. 1998 Jul 1;54(Pt 4):522-46. PMID:9761848
Page seeded by OCA on Tue Nov 20 19:41:44 2007