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The crystal structure of pseudoazurin from Methylobacterium extorquens AM1 (PAZAM1) has been solved by the molecular replacement method using copper-copper distances as translation parameters, which were obtained from difference Patterson maps calculated with the synchrotron radiation data containing the multiwavelength anomalous-dispersion effect. The structure refinement was carried out by the use of molecular dynamics optimization and the restrained least-squares method. The final crystallographic R factor was 19.9% for the 14 365 reflections greater than 3sigma between 1.5 and 8.0 A resolution. This report describes the characteristic features of the structure of PAZAM 1 as well as the effectiveness of synchrotron radiation for structure analysis of metalloproteins. The environment of the metal active site and the structural differences among blue-copper proteins are discussed.

a b s t r a c tHydrothermal synthesis in the M/Mo/O (M ¼ Co,Ni) system was investigated. Novel transition metal tetramolybdate dihydrates MMo 4 O 13 Á 2H 2 O (M ¼ Co,Ni), having an interesting pillared layer structure, were found. The molybdates crystallize in the triclinic system with space group PÀ1, Z ¼ 1 with unit cell (6)1 for NiMo 4 O 13 Á 2H 2 O The structure is composed of two-dimensional molybdenum-oxide (2D Mo-O) sheets pillared with CoO 6 octahedra. The 2D Mo-O sheet is made up of infinite straight ribbons built up by corner-sharing of four molybdenum octahedra (two MoO 6 and two MoO 5 OH 2 ) sharing edges. These infinite ribbons are similar to the straight ones in triclinic-K 2 Mo 4 O 13 having 1D chain structure, but are linked one after another by corner-sharing to form a 2D sheet structure, like the twisted ribbons in BaMo 4 O 13 Á 2H 2 O (or in orthorhombic-K 2 Mo 4 O 13 ) are.

Single‐phase crystalline NiMoO4·nH2O is synthesized hydrothermally (autoclave, 453 K, 1 d, 45% yield) from aqueous suspensions of amorphous NiMoO4·nH2O obtained by calcination of stoichiometric mixtures of (NH4)6Mo7O24 and Ni(NO3)2 (453 K, 1 d).

Cobalt I 7200 Transition Metal Tetramolybdate Dihydrates MMo4O13·2H2O (M: Co, Ni) Having a Novel Pillared Layer Structure. -The title compounds (III) crystallize in the triclinic space group P1 with Z = 1 (single crystal XRD). Tetranuclear units of four edge-sharing MoO6 octahedra are connected via corners to ribbons, which are further linked by corner sharing to form molybdenum oxide sheets. These Mo-O sheets are pillared by CoO6 octahedra. -(EDA*, K.; OHSHIRO, Y.; NAGAI, N.; SOTANI, N.; WHITTINGHAM, M. S.; J. Solid State Chem. 182 (2009) 1, 55-59; Dep. Chem., Grad. Sch. Sci., Kobe Univ., Nada, Kobe 657, Japan; Eng.) -Schramke 13-021