A metal-binding site in the catalytic subunit of anaerobic ribonucleotide reductase.
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.
Logan
Derek T
DT
Department of Molecular Biophysics, Lund University, Box 124, 221 00 Lund, Sweden. derek.logan@mbfys.lu.se
Mulliez
Etienne
E
Larsson
Karl-Magnus
KM
Bodevin
Sabrina
S
Atta
Mohamed
M
Garnaud
Pierre Emmanuel
PE
Sjoberg
Britt-Marie
BM
Fontecave
Marc
M
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
D017931:DNA Primers; D021122:Protein Subunits; D011994:Recombinant Proteins; D012264:Ribonucleotide Reductases