Acta Crystallographica Section DActa Crystallographica Section D: Biological Crystallography welcomes the submission of papers covering any aspect of structural biology with a particular emphasis on the structures of biological macromolecules and the methods used to determine them. Reports on new protein structures are particularly encouraged, as are papers on crystallographic binding studies, structural analysis of mutants and other structure-function studies. Refinements of previously known structures may be published if...Direct interaction between a human digestive protease and the mucoadhesive poly(acrylic acid)- June 18, 2008 Carboxypeptidase A1 has been the subject of extensive research in the last 30y and is one of the most widely studied zinc metalloenzymes. However, the three-dimensional structure of the human form of the enzyme is not yet available. This report describes the three-dimensional structure of human carboxypeptidase A1 (hCPA1) derived from crystals that belong to the tetragonal space group P43212 and diffract to 1.6 resolution. A description of the ternary complex hCPA1Zn2+poly(acrylic acid) is...http://scripts.iucr.org/cgi-bin/paper?hv5106 High-resolution structure of unbound human immunodeficiency virus 1 subtype C protease: implications of flap dynamics and drug resistance- June 18, 2008 The X-ray crystal structure of the unbound state of human immunodeficiency virus 1 (HIV-1) subtype C protease (C PR) has been determined to 1.20 resolution in the tetragonal space group P41212, with one monomer per asymmetric unit and unit-cell parameters a = 46.7, c = 100.8, allowing full anisotropic least-squares refinement. The refined model has a conventional R factor of 14.1% for all reflections and estimated standard deviations in bond lengths and angles for all main-chain non-H atoms of..http://scripts.iucr.org/cgi-bin/paper?hv5105 Structure determination of an anti-HIV-1 Fab 447-52Dpeptide complex from an epitaxially twinned data set- June 18, 2008 Although antibodies against the third variable loop (V3) of the HIV-1 viral envelope glycoprotein are among the first neutralizing antibodies to be detected in infected individuals, they are normally restricted in their specificity. X-ray crystallographic studies of V3-specific antibodies have contributed to a more thorough understanding of recognition of this epitope and of conserved features in the V3 loop that could potentially aid in the design of a multi-component vaccine. The human...http://scripts.iucr.org/cgi-bin/paper?ea5083 Structures of Mycobacterium tuberculosisfolylpolyglutamate synthase complexed with ADP and AMPPCP- June 18, 2008 Folate derivatives are essential vitamins for cell growth and replication, primarily because of their central role in reactions of one-carbon metabolism. Folates require polyglutamation to be efficiently retained within the cell and folate-dependent enzymes have a higher affinity for the polyglutamylated forms of this cofactor. Polyglutamylation is dependent on the enzyme folylpolyglutamate synthetase (FPGS), which catalyzes the sequential addition of several glutamates to folate. FPGS is...http://scripts.iucr.org/cgi-bin/paper?gx5127 On the determinants of amide backbone exchange in proteins: a neutron crystallographic comparative study- June 18, 2008 The hydrogendeuterium-exchange (HDX) method, coupled with neutron diffraction, is a powerful probe for investigating molecular dynamics. In the present report, general determinants of HDX are proposed based on 12 deposited neutron protein structures. The parameters that correlate best with HDX are the depth within the protein structure of the amide N atom and the secondary-structure type. Both the B factor of the amide N atom and the ratio BB correlate moderately. However, solvent accessibility.http://scripts.iucr.org/cgi-bin/paper?be5107 A general method for phasing novel complex RNA crystal structures without heavy-atom derivatives- June 18, 2008 The crystallographic phase problem Muirhead & Perutz (1963), Nature (London), 199, 633638 remains the single major impediment to obtaining a three-dimensional structure of a macromolecule once suitable crystals have been obtained. Recently, it was found that it was possible to solve the structure of a 142-nucleotide L1 ligase ribozyme heterodimer that possesses no noncrystallographic symmetry without heavy-atom derivatives, anomalous scattering atoms or other modifications and without a...http://scripts.iucr.org/cgi-bin/paper?wd5091 1.6 structure of an NAD+-dependent quinate dehydrogenase from Corynebacterium glutamicum- June 18, 2008 To date, three different functional classes of bacterial shikimatequinate dehydrogenases have been identified and are referred to as AroE, SDH-L and YdiB. The enzyme AroE and the catalytically much slower SDH-L clearly prefer NADP+NADPH as the cosubstrate and are specific for (dehydro-)shikimate, whereas in YdiB the differences in affinity for NADP+NADPH versus NAD+NADH as well as for (dehydro-)shikimate versus (dehydro-)quinate are marginal. These three subclasses have a similar...http://scripts.iucr.org/cgi-bin/paper?hm5065 Structure and sugar-specificity of basic winged-bean lectin: structures of new disaccharide complexes and a comparative study with other known disacch- June 18, 2008 Crystal structures of the complexes of basic winged-bean agglutinin with the disaccharides Gal1-4Gal (galabiose), Gal1-6Glc (mellibiose) and Gal1-4Gal-Et have been determined and the complex with Gal1-2Gal has been modelled. The interactions of the nonreducing Gal with the lectin at the primary site are the same as those in the known complexes with disaccharides having the 13 linkage. The second residue in Gal1-4Gal and Gal1-6Glc forms a water bridge to the lectin, while the ethyl group in...http://scripts.iucr.org/cgi-bin/paper?mv5012 Structural basis for the high-affinity binding of pyrrolotriazine inhibitors of p38 MAP kinase- June 18, 2008 The crystal structure of unphosphorylated p38 MAP kinase complexed with a representative pyrrolotriazine-based inhibitor led to the elucidation of the high-affinity binding mode of this class of compounds at the ATP-binding site. The ligand binds in an extended conformation, with one end interacting with the adenine-pocket hinge region, including a hydrogen bond from the carboxyl O atom of Met109. The other end of the ligand interacts with the hydrophobic pocket of the binding site and with the.http://scripts.iucr.org/cgi-bin/paper?en5295 Exploiting the anisotropy of anomalous scattering boosts the phasing power of SAD and MAD experiments- June 18, 2008 The X-ray polarization anisotropy of anomalous scattering in crystals of brominated nucleic acids and selenated proteins is shown to have significant effects on the diffraction data collected at an absorption edge. For conventionally collected single- or multi-wavelength anomalous diffraction data, the main manifestation of the anisotropy of anomalous scattering is the breakage of the equivalence between symmetry-related reflections, inducing intensity differences between them that can be...http://scripts.iucr.org/cgi-bin/paper?wd5090 |