The Allosteric Regulatory Mechanism of the Escherichia coli MetNI Methionine ATP Binding Cassette (ABC) Transporter

Yang, Ji-Young; Rees, Douglas C.

doi:10.1074/jbc.m114.603365

Cited by 24 publications

(19 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As we held expression levels constant with an exogenous promoter, we demonstrated that a phoU deletion mutant accumulated Pi at a higher rate than cells expressing the pstSCAB genes and phoU. Other ABC transporters, such as the methionine transporter, have regulatory domains that respond to the cytoplasmic concentrations of transported substrates and function as sites of allosteric inhibition of transport [86][87][88]. We proposed that PhoU plays a similar role for Pi transport in E. coli.…”

Section: The Response To High Levels Of Extracellular Pimentioning

confidence: 88%

Molecular Mechanisms of Phosphate Homeostasis in <i>Escherichia coli</i>

McCleary¹

2017

≪i>Escherichia Coli

14
2
12
0

View full text Add to dashboard Cite

Life's processes absolutely require inorganic phosphate for structural and energetic purposes. Escherichia coli has developed sophisticated mechanisms to acquire phosphate and to maintain intracellular amounts at optimal levels. The processes by which these simple cells maintain stable intracellular concentrations of phosphate are termed phosphate homeostasis, which involves mechanisms to balance the import, assimilation, sequestration, and export of phosphate. This chapter introduces the proteins involved in phosphate homeostasis and reviews information concerning the multiple phosphate transporters and the mechanisms by which they are regulated. It also introduces new concepts of how this bacterium responds to elevated extracellular levels of phosphate and presents a model for the integration of all of these processes to achieve homeostasis. The predominant importers are PitA, PitB, and the PstSCAB complex. Assimilation, or the incorporation of Pi into organic molecules, occurs primarily through the formation of ATP. Gene regulation relies on the PhoB/PhoR two-component system and the formation of a signaling complex at the membrane. The amount of intracellular phosphate can be fine-tuned through the formation or degradation of polyphosphate. Polyphosphate formation requires adequate supplies of ATP. In addition, when intracellular phosphate levels become too high, phosphate can be exported through PitA, PitB, or the YjbB transporters.

show abstract

Section: The Response To High Levels Of Extracellular Pimentioning
confidence: 88%

Molecular Mechanisms of Phosphate Homeostasis in <i>Escherichia coli</i>
McCleary¹
2017
≪i>Escherichia Coli
14
2
12
0
View full text Add to dashboard Cite

show abstract

“…38,45 In addition to substrate-binding protein mediated activation, ABC transporters can also be regulated by additional domains, for example, regulatory domains that control the interaction of the NBDs in cis. 46,47 Exporters can also be allosterically regulated by the respective ligands. [48][49][50] In the inward-facing conformation, the NBDs can be quite separated, suggesting that ligand binding at the inward-facing cavity in the TMDs helps trigger a conformational change that brings the NBDs in closer proximity.…”

Section: Abc Transportersmentioning
confidence: 99%

Invited review: Architectures and mechanisms of ATP binding cassette proteins
Hopfner
¹

2016
Biopolymers
58
1
49
0
View full text Add to dashboard Cite

ATP binding cassette (ABC) ATPases form chemo-mechanical engines and switches that function in a broad range of biological processes. Most prominently, a very large family of integral membrane NTPases -ABC transporters -catalyzes the import or of a diverse molecules across membranes. ABC proteins are also critical components of the chromosome segregation, recombination and DNA repair machineries and regulate or catalyze critical steps of ribosomal protein synthesis. Recent structural and mechanistic studies draw interesting architectural and mechanistic parallels between diverse ABC proteins. Here I review the current state of our understanding how NTP-dependent conformational changes of ABC proteins drive diverse biological processes.

show abstract

“…It is therefore of no surprise that decades of research were dedicated to understanding their structure and function. Despite the diversity of their physiological roles and substrate recognition profiles (12)(13)(14)(15)(16)(17) ABC transporters share a common basic architecture, minimally comprising of two intracellular nucleotidebinding domains (NBDs) that bind and hydrolyze ATP, and two transmembrane domains (TMDs) that form a substrate-translocation pathway (18)(19)(20)(21). ATP is bound at two composite sites formed at the interface of the NBDs, and proper formation of the ATP-binding sites requires that the NBDs close into a tight head-to-tail sandwich (22).…”

Section: Introductionmentioning
confidence: 99%

Substrate recognition and ATPase activity of the E. coli cysteine/cystine ABC transporter YecSC-FliY
Sabrialabed
¹
,
Yang
²
,
Yariv
³

et al. 2020
Journal of Biological Chemistry
Self Cite
14
0
15
2
View full text Add to dashboard Cite

Sulfur is essential for biological processes such as amino acid biogenesis, iron–sulfur cluster formation, and redox homeostasis. To acquire sulfur-containing compounds from the environment, bacteria have evolved high-affinity uptake systems, predominant among which is the ABC transporter family. Theses membrane-embedded enzymes use the energy of ATP hydrolysis for transmembrane transport of a wide range of biomolecules against concentration gradients. Three distinct bacterial ABC import systems of sulfur-containing compounds have been identified, but the molecular details of their transport mechanism remain poorly characterized. Here we provide results from a biochemical analysis of the purified Escherichia coli YecSC-FliY cysteine/cystine import system. We found that the substrate-binding protein FliY binds l-cystine, l-cysteine, and d-cysteine with micromolar affinities. However, binding of the l- and d-enantiomers induced different conformational changes of FliY, where the l- enantiomer–substrate-binding protein complex interacted more efficiently with the YecSC transporter. YecSC had low basal ATPase activity that was moderately stimulated by apo FliY, more strongly by d-cysteine–bound FliY, and maximally by l-cysteine– or l-cystine–bound FliY. However, at high FliY concentrations, YecSC reached maximal ATPase rates independent of the presence or nature of the substrate. These results suggest that FliY exists in a conformational equilibrium between an open, unliganded form that does not bind to the YecSC transporter and closed, unliganded and closed, liganded forms that bind this transporter with variable affinities but equally stimulate its ATPase activity. These findings differ from previous observations for similar ABC transporters, highlighting the extent of mechanistic diversity in this large protein family.

show abstract

The Allosteric Regulatory Mechanism of the Escherichia coli MetNI Methionine ATP Binding Cassette (ABC) Transporter

Cited by 24 publications

References 35 publications

Molecular Mechanisms of Phosphate Homeostasis in <i>Escherichia coli</i>

Molecular Mechanisms of Phosphate Homeostasis in <i>Escherichia coli</i>

Invited review: Architectures and mechanisms of ATP binding cassette proteins

Substrate recognition and ATPase activity of the E. coli cysteine/cystine ABC transporter YecSC-FliY

Contact Info

Product

Resources

About