Biochemical and functional analysis of ExoR proteins with single-amino-acid mutations, ExoRL81A, ExoRW79A, and ExoRY87A, expressed from plasmids pHC571, pHC572, and pHC573, respectively, in the exoR108-chvI109 mutant for Western blotting (A) and in the exoR95 mutant for their effects on succinoglycan production (B and C) and swimming ability (D).