tmRNA is found in the usual one-piece form in most cyanobacteria, but a small clade has an unusual two-piece form, resulting from processing of a circularly permuted precursor RNA. Here, the secondary structure of the cyanobacterial one-piece tmRNA is established by phylogenetic sequence comparison; it deviates from most tmRNAs in having an extra (fifth) pseudoknot and a branched structure at t...

A high-resolution look at where histones touch DNA reveals a surprisingly intricate, dynamic, and modular nucleosome. Three advances in the study by Rhee et al. include unexpected interactions between the H3 tail and linker DNA, new evidence for existence of subnucleosomal particles, and asymmetric patterns of histone modification within a single nucleosome that correspond to the direction of t...