Biological structures of the year

The nuclear pore complex is enormous, both in size and biological importance. The 1,000-Å-wide complex is the gatekeeper for the cell’s nucleus, responsible for moving thousands of proteins, RNA molecules, and nutrients in and out of the organelle. Two independent teams, one led by Martin Beck of the European Molecular Biology Laboratory and the other led by André Hoelz of California Institute of Technology, visualized the overall architecture of the membrane-embedded mega-machinery, which includes 30 types of nucleoporin proteins with a combined mass topping 100 million daltons (Science 2016, DOI: 10.1126/science.aaf0643; DOI: 10.1126/science.aaf1015).

Surprisingly, a DNA enzyme, or DNAzyme, had never been visualized before this year because researchers had been unable to crystallize this type of catalyst. The feat comes thanks to a team led by Claudia Höbartner and Vladimir Pena of the Max Planck Institute for Biophysical Chemistry, who reported the structure of a DNAzyme called 9DB1, which specializes in stitching together RNA strands. The new structure could enable more rational design of single-stranded DNAzymes for biomedical use (Nature 2016, DOI: 10.1038/nature16471).

Drug developers have been pining for an atomic-resolution image of histone deacetylase 6 (HDAC6), whose matter-of-fact name belies the enzyme’s sexier role as a “sizzling hot target” for cancer chemotherapy, explains the University of Pennsylvania’s David W. Christianson. That’s because interfering with HDAC6’s ability to deacetylate important cell scaffold proteins can disrupt cell division and eventually lead to cell death. Two independent teams, one led by Christianson and the other led by Patrick Matthias of the Friedrich Miescher Institute for Biomedical Research, solved the structure of HDAC6 (Nat. Chem. Biol. 2016, DOI: 10.1038/nchembio.2140; DOI: 10.1038/nchembio.2134).