component of the regulatory network controlling carbon source utilization through ubiquitination and deubiquitination involving creA, creB, creC, creD and acrB. Involved in resistance to acriflavine, and required for normal growth on a range of sole carbon sources, including fructose, cellobiose, raffinose, and starch, and reduced utilization of amino acids, including GABA and beta-alanine, as sole carbon and nitrogen sources. Belongs to the acrB family.