Ribonucleotide reductase in blue-green algae: dependence on adenosylcobalamin

See allHide authors and affiliations

Science  25 Jun 1976:
Vol. 192, Issue 4246, pp. 1343-1344
DOI: 10.1126/science.818711


Ten species of freshwater blue-green algae exhibit an adenosylcobalamin-dependent ribonucleotide reductase, thuse explaining the requirement for cobalt by these organisms. The evidence suggests a phylogenetic affinity between the cyanophytes and bacteria, such as Clostridium and Rhizobium, and the euglenoid flagellates, which also use the cofactor-dependent reductase. In contrast, the ribonucleotide reductase reaction in the few green algae surveyed shows no dependence on cobalamins.