User:Cboursnell/Sandbox/ABG transport

The p-aminobenzoyl-glutamate transporter family includes two putative transporters, the AbgT protein of Escherichia coli and MtrF of Neisseria gonorrhoeae. AbgT expression is apparently cryptic in wild type cells, but when present on a high copy number plasmid, or when expressed at higher levels due to mutation, it allows utilization of p-aminobenzoyl-glutamate as a source of p-aminobenzoate for p-aminobenzoate auxotrophs. p-Aminobenzoate is a constituent of, and a precursor for, the biosynthesis of folic acid. It is not currently known if AbgT is naturally involved in transporting p-aminobenzoyl-glutamate, or if it only becomes involved when under altered regulation. MtrF is an inner membrane protein which, together with the MtrCDE efflux pump, is required for high-level resistance to hydrophobic antimicrobial agents in N. gonorrhoeae. Its role in this process is not known, but it has been suggested that it may be a component of the efflux pump which is dispensible for basal activity, but required for high-level activity.