1wls

Crystal structure of L-asparaginase I homologue protein from Pyrococcus horikoshii

spinqualitylabelsall models 1wls, resolution 2.16Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1wls is a 2 chain structure with sequence from 'pyrococcus shinkaii'. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. NonStd Res: MSE Gene: PH0066 ('Pyrococcus shinkaii') Activity: Asparaginase, with EC number 3.5.1.1 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The crystal structure of the L-asparaginase from the hyperthermophilic archaeon Pyrococcus horikoshii (PhA) was determined by the multiwavelength anomalous diffraction (MAD) method and was refined to a resolution of 2.16 angstroms with a crystallographic R factor and free R factor of 21.1 and 25.3%, respectively. This is the first report of the three-dimensional structure of a type I L-asparaginase. These enyzmes are known as cytosolic L-asparaginases with lower affinities for substrate than the type II L-asparaginases. Although the overall fold of PhA was closely related to the structure of the well characterized type II L-asparaginase, structural differences were also detected. PhA forms a homodimer that corresponds to half the homotetramer of type II L-asparaginases. Structure comparison at the active site reveals that most catalytic residues are conserved except for two residues that recognize the amino group of the substrate. Additionally, a remarkable structural difference is found in the so-called 'active-site flexible loop'. In PhA this loop is stabilized by beta-hairpin formation and by elaborate interactions with the type-I-specific alpha-helical region derived from the other subunit forming the PhA dimer. The flexible loop of the type II enzyme is considered to serve as a mobile gate to the active site. Therefore, the loop stabilization observed in the PhA structure may cause limitation of the access of the substrate to the active site. Structure of the type I L-asparaginase from the hyperthermophilic archaeon Pyrococcus horikoshii at 2.16 angstroms resolution.,Yao M, Yasutake Y, Morita H, Tanaka I Acta Crystallogr D Biol Crystallogr. 2005 Mar;61(Pt 3):294-301. Epub 2005, Feb 24. PMID:15735339 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Asparaginase

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