ABC transport is inactivated by the PTS^Ntr under potassium limitation in Rhizobium leguminosarum 3841

TY - JOUR

T1 - ABC transport is inactivated by the PTSNtr under potassium limitation in Rhizobium leguminosarum 3841

AU - Untiet, Verena

AU - Karunakaran, Ramakrishnan

AU - Krämer, Maria

AU - Poole, Philip

AU - Priefer, Ursula

AU - Prell, Jürgen

PY - 2013/5/28

Y1 - 2013/5/28

N2 - PTS(Ntr) is a regulatory phosphotransferase system in many bacteria. Mutation of the PTS(Ntr) enzymes causes pleiotropic growth phenotypes, dry colony morphology and a posttranslational inactivation of ABC transporters in Rhizobium leguminosarum 3841. The PTS(Ntr) proteins EI(Ntr) and 2 copies of EIIA(Ntr) have been described previously. Here we identify the intermediate phosphocarrier protein NPr and show its phosphorylation by EI(Ntr) in vitro. Furthermore we demonstrate that phosphorylation of EI(Ntr) and NPr is required for ABC transport activation and that the N-terminal GAF domain of EI(Ntr) is not required for autophosphorylation. Previous studies have shown that non-phosphorylated EIIA(Ntr) is able to modulate the transcriptional activation of the high affinity potassium transporter KdpABC. In R. leguminosarum 3841 kdpABC expression strictly depends on EIIA(Ntr). Here we demonstrate that under strong potassium limitation ABC transport is inactivated, presumably by non-phosphorylated EIIA(Ntr). This is to our knowledge the first report where PTS(Ntr) dictates an essential cellular function. This is achieved by the inverse regulation of two important ATP dependent transporter classes.

AB - PTS(Ntr) is a regulatory phosphotransferase system in many bacteria. Mutation of the PTS(Ntr) enzymes causes pleiotropic growth phenotypes, dry colony morphology and a posttranslational inactivation of ABC transporters in Rhizobium leguminosarum 3841. The PTS(Ntr) proteins EI(Ntr) and 2 copies of EIIA(Ntr) have been described previously. Here we identify the intermediate phosphocarrier protein NPr and show its phosphorylation by EI(Ntr) in vitro. Furthermore we demonstrate that phosphorylation of EI(Ntr) and NPr is required for ABC transport activation and that the N-terminal GAF domain of EI(Ntr) is not required for autophosphorylation. Previous studies have shown that non-phosphorylated EIIA(Ntr) is able to modulate the transcriptional activation of the high affinity potassium transporter KdpABC. In R. leguminosarum 3841 kdpABC expression strictly depends on EIIA(Ntr). Here we demonstrate that under strong potassium limitation ABC transport is inactivated, presumably by non-phosphorylated EIIA(Ntr). This is to our knowledge the first report where PTS(Ntr) dictates an essential cellular function. This is achieved by the inverse regulation of two important ATP dependent transporter classes.

KW - ATP-Binding Cassette Transporters/metabolism

KW - Aminoisobutyric Acids/metabolism

KW - Bacterial Proteins/metabolism

KW - Biological Transport

KW - Histidine/metabolism

KW - Mutant Proteins/metabolism

KW - Phosphoenolpyruvate/metabolism

KW - Phosphoenolpyruvate Sugar Phosphotransferase System/metabolism

KW - Phosphorylation/drug effects

KW - Potassium/pharmacology

KW - Protein Structure, Tertiary

KW - Recombinant Fusion Proteins/metabolism

KW - Rhizobium leguminosarum/drug effects

U2 - 10.1371/journal.pone.0064682

DO - 10.1371/journal.pone.0064682

M3 - Journal article

C2 - 23724079

SN - 1932-6203

VL - 8

SP - 1

EP - 9

JO - PLoS ONE

JF - PLoS ONE

IS - 5

M1 - e64682

ER -