In Science this week, investigators from Oak Ridge National Laboratory report on the genetic basis for mercury methylation, the process of converting mercury into the neurotoxin methylmercury, by bacteria. The team examined the genomes of two sulfur-reducing bacteria — Desulfovibrio desulfuricans ND132 and Geobacter sulfurreducens PCA — and found that two genes, if deleted alone or together, abolishes the organisms' ability to process mercury. Because these genes are present in other lineages of bacteria and archaea, the ability to produce methylmercury may be more widespread than previously believed.
Also in Science, a multi-institute team of French researchers publish the crystal structure of papillomavirus proteins, offering a potential new target for fighting the infection, which is known to cause a variety of cancers including cervical cancer. Papillomaviruses rely on a protein called E6 to bind to and deactivate certain host proteins. The scientists determined the structure of both human and bovine E6 proteins bound to their host proteins and described two zinc domains and a linker helix that form a hydrophobic binding site. Mutational inactivation of this site disrupts the oncogenic activities of the E6 proteins, suggesting a new area for therapeutic intervention.