Small RNAs repress expression of polysaccharide utilization loci of gut Bacteroides species

Abstract

Bacteroides species can metabolize numerous plant polysaccharides and host glycans present in the mammalian gut. The regulatory systems governing the induction of particular polysaccharide utilization loci when the cognate glycan is present are known, but how expression is repressed when a higher-priority glycan is present is largely unknown. In this issue of the Journal of Bacteriology, Cao et al. (J. Bacteriol. 198:2410-2418, 2016, http://dx.doi.org/10.1128/JB.00381-16) reveal a conserved mechanism in Bacteroides whereby antisense small RNAs (sRNA) repress expression of genes involved in utilization of host glycans.