An encyclopedic effort to make 3D structures easier to understand.

For the first time in the short history of electronic publication, rotatable and zoomable 3D structures of biomolecules were integrated within the PDF file of the recent TiBS paper ‘Grasping molecular structures through publication-integrated 3D models’ by Kumar and Ziegler et al. [1]. This represents a major step forward in effective and simple communication of complex 3D data, one which has already been expanded into other spheres of science with the recent publication of a ‘3D PDF’ version of an astronomy paper in Nature [2]. The field of structural biology has long suffered from a communication gap between structural specialists and non-specialists. This problem stems, in part, from the complexity of the 3D structures of biomolecules and the difficulty of properly conveying these structures using only 2D pictures in publications. It is evident that today’s most successful, clear and engaging lectures on structural biology employ movies of biomolecules in addition to interactive 3Dmodels embedded within electronic slideshow presentations. Lecturers, being able to immediately gauge their audience’s response to and comprehension of their talks, have recognized the need to include 3D images in their presentations and have found the technology to do so readily available, for example, through the use of PyMOL (www.pymol.org), iSee [3], eMovie [4], POLYVIEW [5,6] and Accelrys Discovery Studio Visualizer 2.0 (http://accelrys.com/products/discovery-studio/ visualization/discovery-studio-visualizer.html). Until the article by Kumar and Ziegler et al. [1], however, scientific publications were still stuck with 2D representations in their papers (for understandable reasons, most notably a lack of a standardized, simple solution for embedding 3D in electronic publications) unless supplemental downloads, such as movie files, were also provided. Although structures described in publications can always be downloaded from the Protein Data Bank [7] and interactively explored in their native 3D using widely available molecular visualization programs, these programs are often inaccessible to non-specialists owing to a steep learning curve (with, in our opinion, FirstGlance in Jmol [http:/ firstglance.jmol.org] being an exception). In the article by Kumar and Ziegler et al. [1], interactive 3D figures contained wholly within the PDF file provide an intuitive and simple way to communicate biomolecular structures to a wide scientific audience in a format that is both portable and usable almost anywhere the reader has access to a