TY - JOUR
T1 - Sensing by the membrane-bound sensor kinase DcuS
T2 - Exogenous versus endogenous sensing of C4-dicarboxylates in bacteria
AU - Scheu, Patrick D.
AU - Kim, Ok Bin
AU - Griesinger, Christian
AU - Unden, Gottfried
PY - 2010/9
Y1 - 2010/9
N2 - Bacteria are able to grow at the expense of both common (succinate, L-malate, fumarate and aspartate) and uncommon (L-tartrate and D-malate) C 4-dicarboxylates, which are components of central metabolism. Two types of sensors/regulators responding to the C4-dicarboxylates function in Escherichia coli, Bacillus, Lactobacillus and related bacteria. The first type represents membrane-integral two-component systems, while the second includes cytoplasmic LysR-type transcriptional regulators. The difference in location and substrate specificity allows the exogenous induction of metabolic genes by common C4-dicarboxylates, and endogenous induction by uncommon C4-dicarboxylates. The two-component sensors, DcuS and CitA, are composed of an extracellular Per-Arnt-Sim (PAS) domain, two transmembrane helices, a cytoplasmic PAS and the kinase domain. The structures of the extracellular PAS domains of DcuS and CitA have been determined in the ligand-bound and the apo form. Binding of the ligand results in closing and compaction of the binding site, and the structural change gives rise to piston-type movement of the adjacent membrane-spanning helix-2, and signal transmission to the cytoplasmic side. For DcuS, a membrane-embedded construct has been developed that suggests (by experimentation and modeling) that plasticity of the cytoplasmic PAS domain is central to signal transduction from the membrane to the kinase. Sensor kinase DcuS of E. coli requires the C 4-dicarboxylate transporters DctA or DcuB as co-sensors for function under aerobic and anaerobic conditions, respectively. DcuB contains a regulatory site that controls the function of DcuS and is independent from the transport region. Therefore, DcuS senses C4-dicarboxylates in two independent modes, responding to the effector concentration and the metabolic flux of extracellular C4-dicarboxylates.
AB - Bacteria are able to grow at the expense of both common (succinate, L-malate, fumarate and aspartate) and uncommon (L-tartrate and D-malate) C 4-dicarboxylates, which are components of central metabolism. Two types of sensors/regulators responding to the C4-dicarboxylates function in Escherichia coli, Bacillus, Lactobacillus and related bacteria. The first type represents membrane-integral two-component systems, while the second includes cytoplasmic LysR-type transcriptional regulators. The difference in location and substrate specificity allows the exogenous induction of metabolic genes by common C4-dicarboxylates, and endogenous induction by uncommon C4-dicarboxylates. The two-component sensors, DcuS and CitA, are composed of an extracellular Per-Arnt-Sim (PAS) domain, two transmembrane helices, a cytoplasmic PAS and the kinase domain. The structures of the extracellular PAS domains of DcuS and CitA have been determined in the ligand-bound and the apo form. Binding of the ligand results in closing and compaction of the binding site, and the structural change gives rise to piston-type movement of the adjacent membrane-spanning helix-2, and signal transmission to the cytoplasmic side. For DcuS, a membrane-embedded construct has been developed that suggests (by experimentation and modeling) that plasticity of the cytoplasmic PAS domain is central to signal transduction from the membrane to the kinase. Sensor kinase DcuS of E. coli requires the C 4-dicarboxylate transporters DctA or DcuB as co-sensors for function under aerobic and anaerobic conditions, respectively. DcuB contains a regulatory site that controls the function of DcuS and is independent from the transport region. Therefore, DcuS senses C4-dicarboxylates in two independent modes, responding to the effector concentration and the metabolic flux of extracellular C4-dicarboxylates.
KW - C-dicarboxylate
KW - DcuB
KW - DcuS
KW - extracellular sensing
KW - fumarate
KW - intracellular sensing
KW - sensor kinase
KW - succinate
KW - TtdR
UR - http://www.scopus.com/inward/record.url?scp=77957559402&partnerID=8YFLogxK
U2 - 10.2217/fmb.10.103
DO - 10.2217/fmb.10.103
M3 - Review article
C2 - 20860483
AN - SCOPUS:77957559402
SN - 1746-0913
VL - 5
SP - 1383
EP - 1402
JO - Future Microbiology
JF - Future Microbiology
IS - 9
ER -