title: Cloning, expression, characterisation and three-dimensional structure determination of Caenorhabditis elegans spermidine synthase.
abstract: The polyamine synthesis enzyme spermidine synthase (SPDS) has been cloned from the model nematode Caenorhabditis elegans. Biochemical characterisation of the recombinantly expressed protein revealed a high degree of similarity to other eukaryotic SPDS with the exception of a low affinity towards the substrate decarboxylated S-adenosylmethionine (Km = 110 microM) and a less pronounced feedback inhibition by the second reaction product 5'-methylthioadenosine (IC50 = 430 microM). The C. elegans protein that carries a nematode-specific insertion of 27 amino acids close to its N-terminus was crystallized, leading to the first X-ray structure of a dimeric eukaryotic SPDS.
authors.affiliation: Department of Molecular Biophysics, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden.
authors.forename: Veronica T
authors.initials: VT
authors.lastname: Dufe
authors.forename: Kai
authors.initials: K
authors.lastname: Lüersen
authors.forename: Marie-Luise
authors.initials: ML
authors.lastname: Eschbach
authors.forename: Nashya
authors.initials: N
authors.lastname: Haider
authors.forename: Tobias
authors.initials: T
authors.lastname: Karlberg
authors.forename: Rolf D
authors.initials: RD
authors.lastname: Walter
authors.forename: Salam
authors.initials: S
authors.lastname: Al-Karadaghi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D019281:Dimerization; D025461:Feedback, Physiological; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011436:Spermidine Synthase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D011436:Spermidine Synthase