muramidase and molybdenum-cofactor

The human mitochondrial amidoxime reducing component (hmARC) is a molybdenum cofactor-dependent enzyme that is involved in the reduction of a diverse range of N-hydroxylated compounds of either physiological or xenobiotic origin. In this study, the use of a fusion-protein approach with T4 lysozyme (T4L) to determine the structure of this hitherto noncrystallizable enzyme by X-ray crystallography is described. A set of four different hmARC-T4L fusion proteins were designed. Two of them contained either an N-terminal or a C-terminal T4L moiety fused to hmARC, while the other two contained T4L as an internal fusion partner tethered to the hmARC enzyme between two predicted secondary-structure elements. One of these internal fusion constructs could be expressed and crystallized successfully. The hmARC-T4L crystals diffracted to 1.7 Å resolution using synchrotron radiation and belonged to space group P2

Topics: Amino Acid Sequence; Coenzymes; Crystallization; Humans; Metalloproteins; Mitochondrial Proteins; Molybdenum Cofactors; Muramidase; Oxidoreductases; Peptide Fragments; Pteridines; X-Ray Diffraction