Novel Missense Mutations That Affect the Transport Function of MalK, the ATP-Binding-Cassette Subunit of the Salmonella enterica Serovar Typhimurium Maltose Transport System

We report on novel mutations in the malK gene of Salmonella enterica serovar Typhimurium, encoding the ATPase subunit of the maltose transporter (MalFGK(2)). Biochemical analysis suggests that (i) L86 might be involved in a signaling step during substrate translocation and (ii) E306 may be critical for the structural integrity of the protein.