2vmj

Type 1 Copper-Binding Loop of Nitrite Reductase mutant: 130- CAPEGMVPWHVVSGM-144 to 130-CTPHPFM-136

spinqualitylabelsall models 2vmj, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2vmj is a 1 chain structure with sequence from Achromobacter xylosoxidans. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.5Å Ligands: EPE, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function O68601_ALCXX 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 long 15-residue type 1 copper-binding loop of nitrite reductase has been replaced with that from the cupredoxin amicyanin (7 residues). This sizable loop contraction does not have a significant effect on the spectroscopy, and therefore, the structures of both the type 1 and type 2 Cu(II) sites. The crystal structure of this variant with Zn(II) at both the type 1 and type 2 sites has been determined. The coordination geometry of the type 2 site is almost identical to that found in the wild-type protein. However, the structure of the type 1 centre changes significantly upon metal substitution, which is an unusual feature for this class of site. The positions of most of the coordinating residues are altered of which the largest difference was observed for the coordinating His residue in the centre of the mutated loop. This ligand moves away from the active site, which results in a more open metal centre with a coordinating water molecule. Flexibility has been introduced into this region of the protein. The 200 mV increase in the reduction potential of the type 1 copper site indicates that structural changes upon reduction must stabilise the cuprous form. The resulting unfavourable driving force for electron transfer between the two copper sites, and an increased reorganisation energy for the type 1 centre, contribute to the loop variant having very little nitrite reductase activity. The extended type 1 copper-binding loop of this enzyme makes a number of interactions that are important for maintaining quaternary structure. The importance of the long type 1 copper-binding loop of nitrite reductase for structure and function.,Sato K, Firbank SJ, Li C, Banfield MJ, Dennison C Chemistry. 2008;14(19):5820-8. PMID:18491346 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Nitrite reductase 3D structures

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