Crystallization and preliminary X-ray diffraction analysis of spermidine synthase fromHelicobacter pylori

Abstract

Polyamines, such as putrescine, spermidine and spermine, are essential for the regulation of cell proliferation and differentiation in most organisms. Spermidine synthase catalyzes the transfer of the aminopropyl group from decarboxylated S-adenosylmethionine to putrescine in the biosynthesis of spermidine. In this study, spermidine synthase of Helicobacter pylori has been overexpressed in Escherichia coli and purified. Two kinds of spermidine synthase crystals were obtained. One belongs to the monoclinic P2(1) space group, with unit-cell parameters a = 62.78, b = 58.24, c = 74.28 A, beta = 90.9 degrees , and the other belongs to the orthorhombic C222(1) space group, with unit-cell parameters a = 100.43, b = 128.55, c = 143.60 A.

Aminopropyltransferases Involved in Polyamine Biosynthesis Localize Preferentially in the Nucleus of Plant Cells

“…To further validate our positive data of homodimer assembly by BiFC, we analyzed by gel filtration the behaviour of recombinant purified enzymes showing their capability to form homodimers in vitro (Figure 7). In agreement with our results, to date all characterized aminopropyltransferases are homodimers [28], [29], [30], [31], [32] with the only exception of acute thermophiles, where aminopropyltransferases display a tetramer structure formed by pairs of homodimers [33]. Detailed structural analysis of aminopropyltransferase enzymes bound to substrates, products, and inhibitors have provided valuable information with regard to structural dimerization requirements that involve either the N-terminal region for human SPMS [32] or both the N-terminal and the C-terminal domains for the human SPDS enzyme [31].…”

Crystal Structure of Plasmodium falciparum Spermidine Synthase in Complex with the Substrate Decarboxylated S-adenosylmethionine and the Potent Inhibitors 4MCHA and AdoDATO

“…[22][23][24] SPDS from several sources have been crystallized and their structures solved by X-ray crystallography. [25][26][27] In order to get an insight into the structureactivity properties of P. falciparum SPDS (pfSPDS), in the present work we have determined the structure of the apo-pfSPDS as well as the structures of the complexes of pfSPDS with the substrate dcAdoMet and the inhibitors AdoDATO and 4MCHA.…”