Essentiality, not expressiveness, drives gene-strand bias in bacteria

Abstract

Preferential positioning of bacterial genes in the leading strand was thought to result from selection to avoid high head-on collision rates between DNA and RNA polymerases. Here we show, however, that in Bacillus subtilis and Escherichia coli, essentiality (the transcript product), not expressiveness (the collision rate), selectively drives the biased gene distribution.