Pathogens may evade immune response with metal-free enzyme required for DNA replication
(PHYSorg.com Chemistry)

Some bacterial pathogens, including those that cause strep throat and pneumonia, are able to create the components necessary to replicate their DNA without the usually required metal ions. This process may allow infectious bacteria to replicate even when the host`s immune system sequesters iron and manganese ions in an attempt to slow pathogen replication. A new study, which appears in the journal Proceedings of the National Academy of Science, describes a novel subclass of metal-free ribonucleotide reductase enzymes used by these bacteria, an understanding of which could drive the development of new, more effective antibiotics.