PH a pH of 7.3. This is clearly wrong as an acid solution should have a pH of less than 7. Treating the system as a mixture of hydrochloric acid and the amphoteric substance water, a pH of 6.89 results. A weak acid or the conjugate acid of a weak base can be treated using the same formalism. First, an acid dissociation constant is defined as follows. Electrical charges are omitted from subsequent equations for the sake of generality and its value is assumed to have been determined by experiment. This being so, there are three unknown concentrations, [HA], [H] and
6TMS neutral amino acid transporter family multidrug efflux pump of the RND superfamily (TC #2.A.6.2)) and the "mar" regulon itself, and (3) MarB, a small protein of 71 amino acyl residues of unknown function. A periplasmic binding protein, MppA, essential for the uptake of the cell wall murein tripeptide, L-alanyl-γ-D-glutamyl-"meso"-diaminopimelate via the Opp permease, regulates "mar" regulon expression. Loss of MppA causes overproduction of MarA which activates "acrAB", causing pleiotropic drug resistance. MppA probably functions upstream of MarA in a signal transduction pathway that negatively controls expression of the "marRAB" operon. 6TMS neutral amino acid transporter family The 6TMS Neutral Amino Acid Transporter (NAAT) Family (TC#