Revised Model for Enterococcus faecalis fsr Quorum-Sensing System: the Small Open Reading Frame fsrD Encodes the Gelatinase Biosynthesis-Activating Pheromone Propeptide Corresponding to Staphylococcal AgrD

Abstract

ABSTRACT Gelatinase biosynthesis-activating pheromone (GBAP) is an autoinducing peptide involved in Enterococcus faecalis fsr quorum sensing, and its 11-amino-acid sequence has been identified in the C-terminal region of the 242-residue deduced fsrB product (J. Nakayama et al., Mol. Microbiol. 41:145-154, 2001). In this study, however, we demonstrated the existence of fsrD , encoding the GBAP propeptide, which is in frame with fsrB but is translated independently of fsrB . It was also demonstrated that FsrB′, an FsrD segment-truncated FsrB, functions as a cysteine protease-like processing enzyme to generate GBAP from FsrD. This revised model is consistent with the staphylococcal agr system.