Nature of 25 Feb 2010

Two interesting papers in the issue of 25 Feb of Nature:

- a study of Chinese dinosaur fossils, in which melanosomes, organelles that help give feathers their colour, are found.

- and a study of microRNA evolution, in which presence of certain ancient microRNAs is correlated with cell-type.

Solution NMR vs Crystallography resolved by solid state NMR

On page 689-692 In the 4 Feb issue of Nature Cady et al. describe the solid state NMR structure of the influenza virus M2 proton channel in complex with amantadine (an inhibitor) in a lipid bilayer. From solution NMR studies four binding sites had previously been identified, although a high resolution crystal structure identified a single binding site in a different place (see references in the paper).

The solid state NMR structure identifies a single high-affinity binding site and four low-affinity binding sites at locations as shown in the previous studies. This shows both solution NMR and Crystallography were "right", although the second one perhaps a bit more so, because it appears the single high-affinity binding site is more biologically relevant.

A roundabout way to obtain protein structural information

In the paper "Rational design of a structural and functional nitric oxide reductase" Yeung et al. describe a way to get structural information on an enzyme, nitric oxide reductase, which could not be crystallised. They mutated sperm whale myoglobin to yield the same enzymatic activity and then crystallised that... Not as nice as crystallising the real thing of course, but if it's the only thing that works...