In Science Journals.

Highlights from the family of journals.

In Science Journals.

Highlights from the family of journals.

In Science Journals.

Highlights from the family of journals.

In Science Journals.

Highlights from the family of journals.

In Science Journals.

Highlights from the family of journals.

In Science Journals.

Highlights from the family of journals.

In Science Journals.

Highlights from the family of journals.

In Science Journals.

Highlights from the family of journals.

Positive charge loading at protein termini is due to membrane protein topology, not a translational ramp.

In the great majority of genomes, the use of positive charge increases, on average, approaching protein N-termini. Such charged residues slow ribosomes by interacting with the negatively charged exit tunnel. This has been proposed to be selectively advantageous as it provides an elongation speed ramp at translational starts.

Positively charged residues are the major determinants of ribosomal velocity.

Both for understanding mechanisms of disease and for the design of transgenes, it is important to understand the determinants of ribosome velocity, as changes in the rate of translation are important for protein folding, error attenuation, and localization. While there is great variation in ribosomal occupancy along even a single transcript, what determines a ribosome's occupancy is unclear. We examine this issue using data from a ribosomal footprinting assay in yeast.

Atypical at skew in Firmicute genomes results from selection and not from mutation.

The second parity rule states that, if there is no bias in mutation or selection, then within each strand of DNA complementary bases are present at approximately equal frequencies. In bacteria, however, there is commonly an excess of G (over C) and, to a lesser extent, T (over A) in the replicatory leading strand. The low G+C Firmicutes, such as Staphylococcus aureus, are unusual in displaying an excess of A over T on the leading strand.