Phosphatidylglycerol Directs Binding and Inhibitory Action of EIIAGlc Protein on the Maltose Transporter

Sequential Action of MalE and Maltose Allows Coupling ATP Hydrolysis to Translocation in the MalFGK2 Transporter

“…Materials-MalFGK 2 , MalE, and EIIA Glc proteins were overexpressed and purified as before (22,23). Reconstitution of MalFGK 2 into proteoliposomes was carried out as described (21).…”

“…Radiolabeled nucleotides [␣- 32 32 P]ATP in ATPase buffer. The quantity of ATP hydrolyzed was determined by TLC as described previously (22), followed by autoradiography and density scanning on a Typhoon imager.…”

Transcription of malP is subject to phosphotransferase system-dependent regulation in Corynebacterium glutamicum

“…Based on the recent identification of the musEFGKI-encoded ABC transporter as the sole uptake system for maltose in C. glutamicum , maltose uptake by the PTS could be excluded and, therefore, a regulatory function of the PTS for the control of maltose metabolism assumed. In contrast to the situation in E. coli, in which the activity of the ABC transporter for maltose is controlled by the PTS (Bao & Duong, 2013;Blüschke et al, 2006;Böhm et al, 2002;Chen et al, 2013;Saier & Roseman, 1976a, b), maltose uptake was not negatively influenced in PTSdeficient C. glutamicum strains. However, we found in C. glutamicum that transcription of malP, which encodes an a-glucan phosphorylase required for maltose utilization (Seibold et al, 2009), depends on PTS activity.…”

“…In both EI-and HPr-deficient E. coli strains maltose uptake by the MalEFGK 2 transporter is inhibited, because the unphosphorylated EIIA Glc binds to the MalK ATPase subunits and, thus, prevents structural rearrangements necessary for ATP hydrolysis and maltose transport (Bao & Duong, 2013;Chen et al, 2013). This inhibition of maltose uptake by unphosphorylated EIIA Glc also takes place when glucose is taken up via the PTS and is the underlying mechanism of inducer exclusion.…”

“…glycerolkinase) and non-PTS transporters such as the lactose permease LacY and the maltose uptake system MalFGK 2 E (Dean et al, 1990;Hurley et al, 1993;Osumi & Saier, 1982). By this means, disruption of the PTS phosphorelay by deletion of ptsI or ptsH leads to the inhibition of maltose uptake in E. coli and S. enterica serovar Typhimurium and, thus, exclusion of the inducer (Bao & Duong, 2013;Blüschke et al, 2006;Chen et al, 2013;Saier & Roseman, 1976a, b;Simoni et al, 1976). Furthermore, PTS components are also directly involved, by protein-protein interactions, in the control of chemotaxis (unphosphorylated EI inhibits CheA autophosphorylation), glycogen metabolism (dephosphorylated HPr binds and activates the glycogen phosphorylase) and s 70 -dependent transcription (in stationary-phase cells HPr forms a tight complex with the anti-s factor Rsd and thereby inhibits complex formation between Rsd and s 70 ) (Lux et al, 1995;Park et al, 2013;Seok et al, 1997).…”