Acta Crystallographica Section F

Structural Biology and Crystallization Communications

Volume 61, Part 10 (October 2005)

crystallization communications

Acta Cryst. (2005). F61, 889-891 [ doi:10.1107/S1744309105027193 ]

Expression, crystallization and preliminary X-ray crystallographic analysis of human agmatinase

K. H. Kim, H. J. Ahn, D. J. Kim, H. H. Lee, J.-Y. Ha, H.-K. Kim, H.-J. Yoon and S. W. Suh

Abstract: Agmatine, which results from the decarboxylation of L-arginine by arginine decarboxylase, is a metabolic intermediate in the biosynthesis of putresine and higher polyamines (spermidine and spermine). Recent studies indicate that agmatine can have several important biochemical effects in humans, ranging from effects on the central nervous system to cell proliferation in cancer and viral replication. Agmatinase catalyses the hydrolysis of agmatine to putresine and urea and is a major target for drug action and development. The human agmatinase gene encodes a 352-residue protein with a putative mitochondrial targeting sequence at the N-terminus. Human agmatinase (residues Ala36-Val352) has been overexpressed as a fusion with both N- and C-terminal purification tags in Escherichia coli and crystallized in the presence of Mn²⁺ and 1,6-diaminohexane at 297 K using polyethylene glycol 4000 as a precipitant. X-ray diffraction data were collected at 100 K to 2.49 Å from a flash-frozen crystal. The crystals are tetragonal, belonging to space group P4₂, with unit-cell parameters a = b = 114.54, c = 125.65 Å, [alpha] = [beta] = [gamma] = 90°. Three monomers are likely to be present in the asymmetric unit, giving a crystal volume per protein weight (V_M) of 3.66 Å³ Da^-1 and a solvent content of 66.4%.

Keywords: agmatinase; agmatine; cell proliferation; 1,6-diaminohexane; polyamine biosynthesis.