News & Views
Standard theories tell us that, at some point in the Universe's evolution, free quarks and gluons must have become bound together into the hadronic matter we see today. But was this transition abrupt or smooth?
doi: 10.1038/443637a
The compound eyes of ancestral flies picked up only one picture point in each facet. The evolution of a means to split up the light-sensitive cells increased this number to seven, boosting the eye's resolution greatly.
doi: 10.1038/nature05209
An effective but counter-intuitive trick to obtain highly ordered protein crystals is to 'seed' particles on disordered, porous surfaces. Computer simulations provide an explanation for the success of this strategy.
doi: 10.1038/443641a
doi: 10.1038/443642b
The finest scale of blood flow through the brain occurs in capillaries. Suspicions that capillary flow is regulated by cells that put the squeeze on these vessels are now borne out by detailed experiments.
doi: 10.1038/443642a
The latest models suggest that atmospheric oxygen could have fluctuated between high and low concentrations once photosynthesis had evolved. But does the geological evidence really support this?
doi: 10.1038/443643a
Pike move between two basins of a British lake to maximize their evolutionary fitness. This adaptive behaviour suggests that habitat selection is more significant in population dynamics than was thought.
doi: 10.1038/443645a
Mitochondria are central to the process of programmed cell death that kills damaged or superfluous cells. Surprisingly, components of the death machinery turn out to be essential for keeping these organelles in shape.
doi: 10.1038/443646a
Articles
doi: 10.1038/nature05111
Elongation factor eEF3 is an ATPase that, in addition to the two canonical factors eEF1A and eEF2, serves an essential function in the translation cycle of fungi. eEF3 is required for the binding of the aminoacyl-tRNA–eEF1A–GTP ternary complex to the ribosomal A-site and has been suggested to facilitate the clearance of deacyl-tRNA from the E-site. Here we present the crystal structure of Saccharomyces cerevisiae eEF3, showing that it consists of an amino-terminal HEAT repeat domain, followed by a four-helix bundle and two ABC-type ATPase domains, with a chromodomain inserted in ABC2. Moreover, we present the cryo-electron microscopy structure of the ATP-bound form of eEF3 in complex with the post-translocational-state 80S ribosome from yeast. eEF3 uses an entirely new factor binding site near the ribosomal E-site, with the chromodomain likely to stabilize the ribosomal L1 stalk in an open conformation, thus allowing tRNA release.
doi: 10.1038/nature05126
Letters
doi: 10.1038/nature05157
doi: 10.1038/nature05147
doi: 10.1038/nature05120
doi: 10.1038/nature05148
doi: 10.1038/nature05169
doi: 10.1038/nature05163
doi: 10.1038/nature05177
doi: 10.1038/nature05128
doi: 10.1038/nature05193
doi: 10.1038/nature05123
doi: 10.1038/nature05162
doi: 10.1038/nature05164
