title: Preliminary crystallographic studies of purine nucleoside phosphorylase from the cariogenic pathogen Streptococcus mutans.
abstract: The punA gene of the cariogenic pathogen Streptococcus mutans encodes purine nucleoside phosphorylase (PNP), which is a pivotal enzyme in the nucleotide-salvage pathway, catalyzing the phosphorolysis of purine nucleosides to generate purine bases and alpha-ribose 1-phosphate. In the present work, the PNP protein was expressed in Escherichia coli strain BL21 (DE3) in a soluble form at a high level. After purification of the PNP enzyme, the protein was crystallized using the sitting-drop vapour-diffusion technique; the crystals diffracted to 1.6 A resolution at best. The crystals belonged to space group H3, with unit-cell parameters a = b = 113.0, c = 60.1 A.
authors.affiliation: Peking University Shenzhen Graduate School, Shenzhen 518055, People's Republic of China.
authors.forename: Qiao Ming
authors.initials: QM
authors.lastname: Hou
authors.forename: Xiang
authors.initials: X
authors.lastname: Liu
authors.forename: Erik
authors.initials: E
authors.lastname: Brostromer
authors.forename: Lan Fen
authors.initials: LF
authors.lastname: Li
authors.forename: Xiao Dong
authors.initials: XD
authors.lastname: Su
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D018360:Crystallography, X-Ray; D017931:DNA Primers / Q000235:genetics; D003731:Dental Caries / Q000382:microbiology; D005798:Genes, Bacterial; D006801:Humans; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011683:Purine-Nucleoside Phosphorylase / Q000737:chemistry* / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics; D013295:Streptococcus mutans / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity
chemical_list: D017931:DNA Primers; D011993:Recombinant Fusion Proteins; D011683:Purine-Nucleoside Phosphorylase