In this paper, Jan Barciszewski and colleagues describe a new extended hammerhead ribozyme HH-2 with a tertiary stabilizing motif constructed on the basis of the tetraloop receptor sequence, and have calculated six unique catalytic core geometry parameters as distances and angles between particular atoms they have called the 'ribozyme fingerprint'.

In this paper, which is freely available to all authors, Ming-Wei Wang and colleagues have studied the distribution of human FPR1 (formyl peptide receptor 1) haplotypes in the Han Chinese population and assessed the variability of biological responses elicited by cyclosporins to these FPR1 haplotypes, describing the novel properties displayed by variants of FPR1 carrying a single amino acid substitution of Leu for Val at position 101.

In this review, Richard Meehan and colleagues explore the emerging interplay between DNA methylation and the PcG (Polycomb group) proteins that act as evolutionarily conserved mediators of cell identity, and discuss how a multifunctional view of DNA modification as an integral part of chromatin organization is modifying our understanding of this epigenetic mark's contribution to transcriptional regulation.

In this accelerated publication, Ulrich Schweizer and colleagues show that, in mammals, Trit1 is a dimethylallyl:tRNA[Ser]Sec transferase and is required for full selenoprotein expression.