title: A metal-binding site in the catalytic subunit of anaerobic ribonucleotide reductase.
abstract: A Zn(Cys)(4) center has been found in the C-terminal region of the crystal structure of the anaerobic class III ribonucleotide reductase (RNR) from bacteriophage T4. The metal center is structurally related to the zinc ribbon motif and to rubredoxin and rubrerythrin. Mutant enzymes of the homologous RNR from Escherichia coli, in which the coordinating cysteines, conserved in almost all known class III RNR sequences, have been mutated into alanines, are shown to be inactive as the result of their inability to generate the catalytically essential glycyl radical. The possible roles of the metal center are discussed in relationship to the currently proposed reaction mechanism for generation of the glycyl radical in class III RNRs.
authors.affiliation: Department of Molecular Biophysics, Lund University, Box 124, 221 00 Lund, Sweden. derek.logan@mbfys.lu.se
authors.forename: Derek T
authors.initials: DT
authors.lastname: Logan
authors.forename: Etienne
authors.initials: E
authors.lastname: Mulliez
authors.forename: Karl-Magnus
authors.initials: KM
authors.lastname: Larsson
authors.forename: Sabrina
authors.initials: S
authors.lastname: Bodevin
authors.forename: Mohamed
authors.initials: M
authors.lastname: Atta
authors.forename: Pierre Emmanuel
authors.initials: PE
authors.lastname: Garnaud
authors.forename: Britt-Marie
authors.initials: BM
authors.lastname: Sjoberg
authors.forename: Marc
authors.initials: M
authors.lastname: Fontecave
mesh_terms: D000595:Amino Acid Sequence; D000693:Anaerobiosis; D017122:Bacteriophage T4 / Q000201:enzymology; D001483:Base Sequence; D001665:Binding Sites; D016384:Consensus Sequence; D018360:Crystallography, X-Ray / Q000379:methods; D017931:DNA Primers; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D004926:Escherichia coli / Q000201:enzymology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012264:Ribonucleotide Reductases / Q000737:chemistry* / Q000378:metabolism*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers; D021122:Protein Subunits; D011994:Recombinant Proteins; D012264:Ribonucleotide Reductases