Geonomics

HapMap version 2.0

Phase II of the human haplotype map (HapMap), characterizing more than 3.1 million single nucleotide polymorphisms (SNPs), has now been released. The data were collected from 270 individuals from diverse backgrounds, and the resulting HapMap has a density of about one SNP per kilobase. This valuable data resource should facilitate studies of human evolution as well as provide insights into the genetic basis of disease.

The International HapMap Consortium Nature 449, 851–861 (2007).

Protein biochemistry

Protein structures from scratch

With an all-atom rebuilding and refinement protocol, Qian and colleagues describe a computational method to improve protein models derived from NMR and X-ray crystallographic data without using any phasing information or homologous structures. Notably, they were also able to successfully predict the structure of a 112-residue protein without using any experimental information other than the protein sequence.

Qian, B. et al. Nature 450, 259–264 (2007).

Chemical biology

Click chemistry without copper

The azide-alkyne reactions, the Staudinger ligation and the copper-catalyzed cycloaddition known as click chemistry are useful bioorthogonal labeling reactions. However, the Staudinger ligation is a rather slow process, and click chemistry requires the use of toxic copper. Baskin and colleagues now solve both problems with the development of a copper-free click chemistry reaction.

Baskin, J.M. et al. Proc. Natl. Acad. Sci. USA 104, 16793–16797 (2007).

Drug discovery

How drugs inhibit telomerases

Anticancer therapies using drugs that interfere with the maintenance of telomeres by binding to their single-stranded ends have shown good in vivo antitumor activity. These drugs were thought to inhibit the telomerase but De Cian and colleagues now show that the drugs inhibit the initial elongation step of the enzyme rather than its activity. This distinction is important when it comes to devising assays to measure the inhibitory potency of these drugs.

De Cian, A. et al. Proc. Natl. Acad. Sci. USA 104, 17347–17352 (2007).

RNA interference

Controlling pests through RNAi

New methods for controlling agricultural pests are urgently needed. Mao et al. and Baum et al. describe how to harness the power of RNA interference to control insect pests on crops. With transgenic crops expressing dsRNA specific for knocking down essential genes in insects these two groups independently showed that oral delivery of dsRNA caused lethality.

Mao, Y.B. et al. Nat. Biotechnol., published online 4 November 2007.

Baum, J.A. et al. Nat. Biotechnol., published online 4 November 2007.