Crystallization and preliminary X-ray crystallographic analysis of a putative agmatinase from Deinococcus radiodurans.

Agmatine, which results from the decarboxylation of arginine by arginine decarboxylase, is a metabolic intermediate in the biosynthesis of putresine and higher polyamines. The enzyme agmatinase catalyses the hydrolysis of agmatine to putresine and urea. Recent studies indicate that agmatinase plays important roles in mammals. Human mitochondrial agmatinase shows a considerable level of sequence similarity to bacterial agmatinases, including a putative agmatinase from Deinococcus radiodurans. The putative agmatinase from D. radiodurans has been overexpressed in Escherichia coli and crystallized at 297 K using polyethylene glycol 3000 as a precipitant. X-ray diffraction data were collected to 1.80 A from a crystal grown in the presence of Mn2+ and 1,6-hexanediamine. The crystals are orthorhombic, belonging to the space group P2(1)2(1)2(1), with unit-cell parameters a = 81.77, b = 131.44, c = 168.85 A, alpha = beta = gamma = 90 degrees. A hexameric molecule is likely to be present in the asymmetric unit, giving a crystal volume per protein weight (VM) of 2.15 A3 Da(-1) and a solvent content of 41.8%.