Bacterial choline-O-sulfate uptake and desulfation

A reusable bacterial two-step module in which choline-O-sulfate is imported and then hydrolyzed by a BetC choline sulfatase to choline, sulfate, and a proton. The module represents the transport-plus-desulfation boundary; downstream oxidation of choline to glycine betaine, transcriptional regulation, and alternative sulfur-starvation pathways are outside scope.

MODULE:bacterial_choline_o_sulfate_uptake_and_desulfationDRAFTCONCRETEMetabolic Pathwaymodules/bacterial_choline_o_sulfate_uptake_and_desulfation.yaml
choline-O-sulfate utilization
PMID:17116241
Uncoupling of choline-O-sulphate utilization from osmoprotection in Pseudomonas putida.
A KT2440 betC deletion retained choline-O-sulfate accumulation but lost its use as a carbon or nitrogen source. This supports BetC in utilization while showing that uptake is BetC-independent; it does not establish the adjacent BetD/BetE candidates as an importer.
This mutant still accumulated intact COS but failed to use this compound as carbon or nitrogen source.
PMID:9736747
Presence of a gene encoding choline sulfatase in Sinorhizobium meliloti bet operon: choline-O-sulfate is metabolized into glycine betaine.
Sinorhizobium genetics and enzyme assays establish BetC as a choline sulfatase that converts choline-O-sulfate to choline.
a new gene (betC) was identified as encoding a choline sulfatase catalyzing the conversion of choline-O-sulfate and, at a lower rate, phosphorylcholine, into choline.
PMID:21369825
Inducible expression of choline sulfatase and its regulator BetR in Pseudomonas sp. ATCC19151.
A second Pseudomonas locus contains BetC beside a PBPb-superfamily BetD and a STAS-domain permease BetE. The paper establishes this recurring architecture but does not directly demonstrate BetD/BetE transport.
Genes encoding potential choline sulfatase (betC), substrate-binding ABC transporter protein (betD), sulfate transporter (betE), and divergent putative transcriptional regulator (betR) were cloned and characterized from strain ATCC19151.
PMID:29458126
Structural and Mechanistic Analysis of the Choline Sulfatase from Sinorhizobium melliloti: A Class I Sulfatase Specific for an Alkyl Sulfate Ester.
Purified Sinorhizobium BetC efficiently hydrolyzes choline-O-sulfate, and its crystal structure defines the choline-sulfatase catalytic exemplar.
Sinorhizobium meliloti choline sulfatase (SmCS) efficiently catalyzes the hydrolysis of alkyl sulfate choline-O-sulfate
UniProtKB:Q88RQ4
Pseudomonas putida KT2440 PP_0075 (BetE candidate)
Q88RQ4 is a multi-pass SLC26A/SulP-family transporter with a STAS domain and is the membrane component proposed for the KT2440 BetDE system.
UniProtKB:Q88RQ3
Pseudomonas putida KT2440 PP_0076 (BetD candidate)
Q88RQ3 is a signal-peptide-bearing periplasmic substrate-binding protein in the choline-transporter substrate-binding family.
UniProtKB:Q88RQ2
Pseudomonas putida KT2440 BetC
Q88RQ2 carries EC 3.1.6.6, GO:0047753, and the InterPro choline-sulfatase family signature.
UniProtKB:O69787
Experimentally characterized Sinorhizobium meliloti BetC
O69787 is the reviewed BetC exemplar linked to the direct genetic and biochemical evidence in PMID:9736747.

The 2006 KT2440 paper described the transporter adjacent to betC as a putative ABC system, but the current Q88RQ4 domain architecture is SLC26A/SulP plus STAS and contains no canonical ABC nucleotide-binding component. The module therefore records BetD and BetE as separate candidate transport-associated proteins, without asserting a physical complex, ABC coupling, or choline-O-sulfate specificity. The betC deletion phenotype shows that choline-O-sulfate can enter KT2440 but does not identify the responsible transporter.

3Nodes
2Parts
0Variant Sets
0Variants
3Annotons
1Connections

Derived QC

Recommended-field compliance

55.6% recommended fields populated
  • module.knowledge_gaps[0] · status (0/1)
  • module.knowledge_gaps[0] · provenance (0/1)
  • module.knowledge_gaps[1] · status (0/1)
  • module.knowledge_gaps[1] · provenance (0/1)

Module deep research

✓ present

  • bacterial_choline_o_sulfate_uptake_and_desulfation-deep-research-openscientist.md (openscientist)

Leaf nodes lacking representative members

✓ every leaf node grounds to a representative protein.

Template conformance

✓ every declared conforms_to bundle matches its template motif.

Gene-review completeness (3/4 grounded genes reviewed)

2 complete review(s) · 3 with deep research · 1 missing review · 0 reviewed but lacking deep research

Gene Review Complete Deep research
betC Q88RQ2 ✓ ✓ ✓
experimentally characterized Sinorhizobium BetC O69787 ✗ — —
PP_0075 Q88RQ4 ✓ ✓ ✓
PP_0076 Q88RQ3 ✓ 3/6 ✓

Details

Context
bacteriaNCBITaxon:2
Bacterial choline-O-sulfate uptake and desulfationMetabolic Pathwaybacterial_choline_o_sulfate_uptake_and_desulfation
choline-O-sulfate utilization
Context
bacteriaNCBITaxon:2

Connections

Some transport route supplies intracellular choline-O-sulfate for BetC hydrolysis; whether BetD or BetE participates is unresolved.
Part 1: candidate choline-O-sulfate import machinery
Candidate BetD/BetE-associated uptake stepTransport Stepbetde_choline_o_sulfate_import

Records two adjacent transport-associated candidates without asserting that they form a complex or transport choline-O-sulfate.

Annotons

BetE SLC26A/SulP transport candidate
bete_transport_candidate
Participant: Family: SLC26A/SulP transporter family
Family:
SLC26A/SulP transporter familyInterPro:IPR001902
Representative Members: Pseudomonas putida KT2440 BetE candidateUniProtKB:Q88RQ4

Function

transmembrane transporter activityGO:0022857

Processes

transmembrane transportGO:0055085

Multi-pass transport candidate adjacent to betC. Its transported substrate and coupling mechanism are not established.

BetD periplasmic binding-protein candidate
betd_binding_candidate
Participant: Family: choline-transporter substrate-binding family
Family:
choline-transporter substrate-binding familyInterPro:IPR017783 Family assignment supports binding of a choline-related ligand, but the physiological ligand and transport partner are unresolved.
Representative Members: Pseudomonas putida KT2440 BetD candidateUniProtKB:Q88RQ3

Processes

transmembrane transportGO:0055085

Locations

periplasmic spaceGO:0042597

Candidate periplasmic substrate-binding protein adjacent to betC; direct ligand binding and coupling to BetE are untested.

Part 2: choline-O-sulfate hydrolysis
BetC choline-O-sulfate hydrolysisReactionbetc_choline_o_sulfate_hydrolysis

Annotons

BetC choline-sulfatase activity
betc_choline_sulfatase_activity
Participant: Family: BetC choline-sulfatase family
Family:
BetC choline-sulfatase familyInterPro:IPR017785
Representative Members: Pseudomonas putida KT2440 BetCUniProtKB:Q88RQ2 experimentally characterized Sinorhizobium BetCUniProtKB:O69787

Function

choline-sulfatase activityGO:0047753
Substrates: choline-O-sulfate water
Products: choline sulfate proton

Cleaves the sulfate ester, releasing choline for downstream metabolism and sulfate for cellular use or excretion.