An Extracytoplasmic Function Sigma Factor Controls Cellulose Utilization by Regulating the Expression of an Outer Membrane Protein in Cytophaga hutchinsonii

Abstract

The common cellulolytic bacterium Cytophaga hutchinsonii uses a unique but poorly understood strategy in order to make use of cellulose. Throughout the process of cellulosic biomass breakdown, outer membrane proteins are thought to play key roles; this is evidenced by CHU_1276, which is required for the utilization of cellulose. However, the regulatory mechanism of its expression is not yet known. We found and characterized an extracytoplasmic function σ factor that is involved in coordinating the cellulolytic response of C. hutchinsonii by directly regulating the expression of CHU_1276 . This study makes a contribution to our understanding of the regulatory mechanism used by C. hut chinsonii in order to adjust its genetic programs and so deal with novel environmental cues.