Crystallization and Preliminary X-Ray Studies on Pseudoazurin from Achromobacter cycloclastes IAM10131

Abstract

New crystals of a blue copper protein, pseudoazurin from denitrifier Achromobacter cycloclastes IAM1013, have been obtained by means of vapor diffusion with ammonium sulfate as a precipitant at pH 6.0 and 4 degrees C. The crystals belong to the orthorhombic system, space group P2(1)2(1)2(1), with unit cell dimensions of a = 56.69(2), b = 61.53(2), and c = 30.20(1) A. The asymmetric unit includes one molecule of pseudoazurin with a Vm value of 2.04 A3/Da. The crystals are so stable against X-ray irradiation that a complete data set up to 1.54 A has been collected using a single native crystal. Solution of the structure was performed by means of the Patterson search techniques, and the current crystallographic R-factor is 17.5% at 3.0 A resolution. Refinement at higher resolution is in progress.

Spectroscopic and Electrochemical Studies on Active-site Transitions of the Type 1 Copper Protein Pseudoazurin from Achromobacter cycloclastes

“…More recently, the x-ray structure of pseudoazurin from A. cycloclastes has been reported ( Fig. 1) (16), and the structure is almost identical to that of pseudoazurin from A. faecalis (11,12) and Pseudomonas AM1 (17).…”

Crystal Structure Determinations of Oxidized and Reduced Pseudoazurins from Achromobacter cycloclastes

“…Data Collection and Processing-The crystallization (0.1 M potassium phosphate buffer (pH 6.0)) and structural analysis of oxidized pseudoazurin from A. cycloclastes were performed as described previously (26). The data with high resolution was collected with synchrotron radiation at the BL6A 2 station of 2.5 GeV energy produced by the storage ring in the Photon Factory, the National Laboratory for High Energy Physics (KEK), Tsukuba, Japan.…”

“…Preliminary crystallographic studies of A. cycloclastes pseudoazurin were reported by Turley et al (25), but the crystals obtained were too thin for x-ray diffraction data to be obtained. We have previously reported the crystallization and preliminary x-ray studies on oxidized pseudoazurin from A. cycloclastes at pH 6.0 (26). In this work single crystals of oxidized and reduced pseudoazurin with high resolutional diffraction spots were obtained at pH 6.0.…”

New molecular packing in a crystal of pseudoazurin fromAlcaligenes faecalis: a double-helical arrangement of blue copper

“…The blue copper site in PAz has a distorted tetrahedral geometry showing a highly anisotropic electron paramagnetic resonance spectrum, which is a mixture of axial and rhombic signals (Abdelhamid et al, 2007;Yamaguchi et al, 2016). As of January 2017, structures of PAzes from Alcaligenes faecalis (Petratos et al, 1987(Petratos et al, , 1988, Achromobacter cycloclastes (Inoue et al, 1993), Methylobacterium extorquens (Inoue et al, 1994), Paracoccus pantrophus (Williams et al, 1995), Hyphomicrobium denitrificans (Hira et al, 2009a) and Shinorhizobium meliloti (Laming et al, 2012) have been reported. PAz from A. faecalis (Af PAz) was the first PAz for which the structure was determined via X-ray crystallography (Petratos et al, 1987), and more than a third of the PAz structures deposited in the Protein Data Bank (PDB) are of PAz from A. faecalis.…”