The repertoire of functional outputs interfaced with the LuxI/LuxR quorum sensing system in engineered Escherichia coli has been expanded to include motility via inducible expression of motB. Appropriate choice of ribosome binding site controlling MotB translation was crucial to achieving control over motility. Biotechnol. Biotechnol. Bioeng. 2008;100: 1251–1255. © 2008 Wiley Periodicals, Inc.