Harnessing free radicals: formation and function of the tyrosyl radical in ribonucleotide reductase.
Ribonucleotide reductases (RNRs) are uniquely responsible for converting nucleotides to deoxynucleotides in all organisms. The cofactor of class-I RNRs comprises a di-iron cluster and a tyrosyl radical, and is essential for initiation of radical-dependent nucleotide reduction. Recently, much progress has been made in understanding the mechanism by which this cofactor is generated in vitro and in vivo, as well as the function of the tyrosyl radical in nucleotide reduction. The Escherichia coli RNR cofactor provides a paradigm for cofactors in other di-iron requiring or tyrosyl-radical-requiring proteins.
Stubbe
J
J
Dept of Chemistry, Massachusetts Institute of Technology, Cambridge 02139, USA. stubbe@mit.edu
Riggs-Gelasco
P
P
D004926:Escherichia coli / Q000201:enzymology; D005609:Free Radicals; D007501:Iron / Q000378:metabolism; D008956:Models, Chemical; D012264:Ribonucleotide Reductases / Q000378:metabolism*; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
D005609:Free Radicals; C066447:tyrosyl radical Y(D); C114979:tyrosyl radical YZ; D014443:Tyrosine; D007501:Iron; D012264:Ribonucleotide Reductases