Methylphosphonate Degradation I
PathBank:SMP0002077
The four-reaction PathBank route converts methylphosphonate through ribosyl phosphonate intermediates to methane and alpha-D-ribose 1,5-bisphosphate using characterized Escherichia coli K-12 proteins. PhnI acts with PhnG, PhnH and PhnL in the source-defined assembly; PhnM, radical-SAM PhnJ and PhnP perform the following reactions. The endpoint is a phosphate ester, not free phosphate or PRPP. The graph uses Rhea charge forms and its activation-associated PhnJ equation, including generic hydrogen donor/acceptor classes. SAM cleavage and reduced [4Fe-4S] are required for the reconstructed radical reaction; one SAM consumed per physiological substrate turnover is not established. The source-defined four-protein assembly is not the full PhnGHIJKL machinery characterized later. This is enzyme chemistry, not a claim of growth by every K-12 strain: phnE phase variation can prevent methylphosphonate uptake.
- Pathway type
- organophosphonate catabolism
- Organism scope
Pathway network
32 nodes · 40 asserted directed edges
Arrows show recorded subject → object relationships, not necessarily metabolic flow. Select a node for details or an arrow for evidence. Scroll, zoom or find a node to explore.
- Reaction / activity
- Chemical / cofactor
- Protein / complex
- Pathway
- Solid arrow: mechanistic relation
- Dashed arrow: membership, location or cofactor relation
Components and activities
| Node | Kind or role | Source direction |
|---|---|---|
Escherichia coli K-12NCBITaxon:83333 | taxon | |
methylphosphonate(1-)CHEBI:68684 | small molecule | |
ATP(4-)CHEBI:30616 | small molecule | |
alpha-D-ribose 1-methylphosphonate 5-triphosphate(5-)CHEBI:68823 | small molecule | |
adenineCHEBI:16708 | small molecule | |
waterCHEBI:15377 | small molecule | |
alpha-D-ribose 1-methylphosphonate 5-phosphate(3-)CHEBI:68686 | small molecule | |
diphosphate(3-)CHEBI:33019 | small molecule | |
hydronCHEBI:15378 | small molecule | |
hydrogen donorCHEBI:17499 | cofactor | |
S-adenosyl-L-methionine zwitterionCHEBI:59789 | small molecule | |
5-phosphonato-alpha-D-ribose cyclic-1,2-phosphate(3-)CHEBI:68687 | small molecule | |
methaneCHEBI:16183 | small molecule | |
5'-deoxyadenosineCHEBI:17319 | small molecule | |
L-methionine zwitterionCHEBI:57844 | small molecule | |
hydrogen acceptorCHEBI:13193 | cofactor | |
alpha-D-ribose 1,5-bisphosphate(4-)CHEBI:68688 | small molecule | |
tetra-mu3-sulfido-tetraironCHEBI:49883 | cofactor | |
manganese(2+)CHEBI:29035 | cofactor | |
zinc(2+)CHEBI:29105 | cofactor | |
Alpha-D-ribose 1-methylphosphonate 5-triphosphate synthase subunit PhnGUniProtKB:P16685 | protein | |
Alpha-D-ribose 1-methylphosphonate 5-triphosphate synthase subunit PhnHUniProtKB:P16686 | protein | |
Alpha-D-ribose 1-methylphosphonate 5-triphosphate synthase subunit PhnIUniProtKB:P16687 | protein | |
Alpha-D-ribose 1-methylphosphonate 5-triphosphate synthase subunit PhnLUniProtKB:P16679 | protein | |
Alpha-D-ribose 1-methylphosphonate 5-triphosphate diphosphataseUniProtKB:P16689 | protein | |
Alpha-D-ribose 1-methylphosphonate 5-phosphate C-P lyaseUniProtKB:P16688 | protein | |
Phosphoribosyl 1,2-cyclic phosphate phosphodiesteraseUniProtKB:P16692 | protein | |
methylphosphonate degradation complexPathBank:SMP0002077/ProteinComplex/4049 | complex | |
PhnG/H/I/L-dependent ribosyl triphosphate transfer to methylphosphonateRHEA:34680 | molecular activity | left to right |
PhnM hydrolysis of ribosyl methylphosphonate triphosphateRHEA:34684 | molecular activity | left to right |
PhnJ C-P cleavage with radical-SAM activation chemistryRHEA:34708 | molecular activity | left to right |
PhnP hydrolysis of ribosyl 1,2-cyclic phosphateRHEA:34796 | molecular activity | left to right |
Mechanistic edges
| Subject | Predicate and description | Object | Evidence |
|---|---|---|---|
methylphosphonate(1-)CHEBI:68684 | consumes | PhnG/H/I/L-dependent ribosyl triphosphate transfer to methylphosphonateRHEA:34680 |
|
ATP(4-)CHEBI:30616 | consumes | PhnG/H/I/L-dependent ribosyl triphosphate transfer to methylphosphonateRHEA:34680 |
|
PhnG/H/I/L-dependent ribosyl triphosphate transfer to methylphosphonateRHEA:34680 | produces | alpha-D-ribose 1-methylphosphonate 5-triphosphate(5-)CHEBI:68823 |
|
PhnG/H/I/L-dependent ribosyl triphosphate transfer to methylphosphonateRHEA:34680 | produces | adenineCHEBI:16708 |
|
alpha-D-ribose 1-methylphosphonate 5-triphosphate(5-)CHEBI:68823 | consumes | PhnM hydrolysis of ribosyl methylphosphonate triphosphateRHEA:34684 |
|
waterCHEBI:15377 | consumes | PhnM hydrolysis of ribosyl methylphosphonate triphosphateRHEA:34684 |
|
PhnM hydrolysis of ribosyl methylphosphonate triphosphateRHEA:34684 | produces | alpha-D-ribose 1-methylphosphonate 5-phosphate(3-)CHEBI:68686 |
|
PhnM hydrolysis of ribosyl methylphosphonate triphosphateRHEA:34684 | produces | diphosphate(3-)CHEBI:33019 |
|
PhnM hydrolysis of ribosyl methylphosphonate triphosphateRHEA:34684 | produces | hydronCHEBI:15378 |
|
alpha-D-ribose 1-methylphosphonate 5-phosphate(3-)CHEBI:68686 | consumes | PhnJ C-P cleavage with radical-SAM activation chemistryRHEA:34708 |
|
hydrogen donorCHEBI:17499 | consumes The Rhea AH2/A pair is generic. The reconstitution used dithionite; no physiological donor or carrier identity is asserted. | PhnJ C-P cleavage with radical-SAM activation chemistryRHEA:34708 |
|
S-adenosyl-L-methionine zwitterionCHEBI:59789 | consumes Coefficient 1 belongs to the Rhea activation-associated reference equation. It does not establish a fixed SAM-to-methylphosphonate turnover ratio in the functioning complex. | PhnJ C-P cleavage with radical-SAM activation chemistryRHEA:34708 |
|
PhnJ C-P cleavage with radical-SAM activation chemistryRHEA:34708 | produces | 5-phosphonato-alpha-D-ribose cyclic-1,2-phosphate(3-)CHEBI:68687 |
|
PhnJ C-P cleavage with radical-SAM activation chemistryRHEA:34708 | produces | methaneCHEBI:16183 |
|
PhnJ C-P cleavage with radical-SAM activation chemistryRHEA:34708 | produces Coefficient 1 belongs to the Rhea activation-associated reference equation. It does not establish a fixed SAM-to-methylphosphonate turnover ratio in the functioning complex. | 5'-deoxyadenosineCHEBI:17319 |
|
PhnJ C-P cleavage with radical-SAM activation chemistryRHEA:34708 | produces Coefficient 1 belongs to the Rhea activation-associated reference equation. It does not establish a fixed SAM-to-methylphosphonate turnover ratio in the functioning complex. | L-methionine zwitterionCHEBI:57844 |
|
PhnJ C-P cleavage with radical-SAM activation chemistryRHEA:34708 | produces The Rhea AH2/A pair is generic. The reconstitution used dithionite; no physiological donor or carrier identity is asserted. | hydrogen acceptorCHEBI:13193 |
|
PhnJ C-P cleavage with radical-SAM activation chemistryRHEA:34708 | produces | hydronCHEBI:15378 |
|
5-phosphonato-alpha-D-ribose cyclic-1,2-phosphate(3-)CHEBI:68687 | consumes | PhnP hydrolysis of ribosyl 1,2-cyclic phosphateRHEA:34796 |
|
waterCHEBI:15377 | consumes | PhnP hydrolysis of ribosyl 1,2-cyclic phosphateRHEA:34796 |
|
PhnP hydrolysis of ribosyl 1,2-cyclic phosphateRHEA:34796 | produces | alpha-D-ribose 1,5-bisphosphate(4-)CHEBI:68688 |
|
PhnP hydrolysis of ribosyl 1,2-cyclic phosphateRHEA:34796 | produces | hydronCHEBI:15378 |
|
methylphosphonate degradation complexPathBank:SMP0002077/ProteinComplex/4049 | has_part This is PathBank’s PhnG/H/I/L assembly for the first reconstructed reaction. No subunit copy number or equivalence to the later full C-P lyase complex is asserted. | Alpha-D-ribose 1-methylphosphonate 5-triphosphate synthase subunit PhnHUniProtKB:P16686 |
|
methylphosphonate degradation complexPathBank:SMP0002077/ProteinComplex/4049 | has_part This is PathBank’s PhnG/H/I/L assembly for the first reconstructed reaction. No subunit copy number or equivalence to the later full C-P lyase complex is asserted. | Alpha-D-ribose 1-methylphosphonate 5-triphosphate synthase subunit PhnLUniProtKB:P16679 |
|
methylphosphonate degradation complexPathBank:SMP0002077/ProteinComplex/4049 | has_part This is PathBank’s PhnG/H/I/L assembly for the first reconstructed reaction. No subunit copy number or equivalence to the later full C-P lyase complex is asserted. | Alpha-D-ribose 1-methylphosphonate 5-triphosphate synthase subunit PhnGUniProtKB:P16685 |
|
methylphosphonate degradation complexPathBank:SMP0002077/ProteinComplex/4049 | has_part This is PathBank’s PhnG/H/I/L assembly for the first reconstructed reaction. No subunit copy number or equivalence to the later full C-P lyase complex is asserted. | Alpha-D-ribose 1-methylphosphonate 5-triphosphate synthase subunit PhnIUniProtKB:P16687 |
|
methylphosphonate degradation complexPathBank:SMP0002077/ProteinComplex/4049 | catalyzes The four proteins support the complete first reaction. PhnI alone has a separate nucleosidase activity, which is not this pathway reaction; no individual accessory subunit is asserted to catalyze the overall transformation alone. The reconstructed reaction used MgATP. This assay condition does not establish a specific magnesium-binding site or obligatory cofactor relation for the assembly, and no magnesium independence is asserted. | PhnG/H/I/L-dependent ribosyl triphosphate transfer to methylphosphonateRHEA:34680 |
|
Alpha-D-ribose 1-methylphosphonate 5-triphosphate diphosphataseUniProtKB:P16689 | catalyzes The primary PhnM assay contained MgCl2 and ZnCl2. Their presence in that assay is retained as a condition, without claiming both are independently established obligatory cofactors. | PhnM hydrolysis of ribosyl methylphosphonate triphosphateRHEA:34684 |
|
Alpha-D-ribose 1-methylphosphonate 5-phosphate C-P lyaseUniProtKB:P16688 | catalyzes The source reconstitution used anaerobic conditions, an iron-sulfur cluster, SAM, dithionite and cleavage of the GST tag. Later mechanistic work distinguishes radical activation from repeated substrate turnover. | PhnJ C-P cleavage with radical-SAM activation chemistryRHEA:34708 |
|
Phosphoribosyl 1,2-cyclic phosphate phosphodiesteraseUniProtKB:P16692 | catalyzes The physiological cyclic ribose-phosphate substrate was established in PMID:21341651; the earlier PMID:19366688 characterized structure and metal-dependent phosphodiesterase activity with other substrates. | PhnP hydrolysis of ribosyl 1,2-cyclic phosphateRHEA:34796 |
|
Alpha-D-ribose 1-methylphosphonate 5-phosphate C-P lyaseUniProtKB:P16688 | has_cofactor CHEBI:49883 identifies the cluster class rather than its oxidation state. The catalytically active reduced state and anaerobic reconstitution conditions are explicit here; Zn observed at this site in aerobic structures is not substituted for the active Fe-S cluster. | tetra-mu3-sulfido-tetraironCHEBI:49883 |
|
Phosphoribosyl 1,2-cyclic phosphate phosphodiesteraseUniProtKB:P16692 | has_cofactor The source metal-preference experiment used bis(p-nitrophenyl)phosphate. Ni2+ also supported activity; this edge does not assert exclusive Mn2+ usage or transfer that substrate-specific comparison to every physiological condition. | manganese(2+)CHEBI:29035 |
|
Phosphoribosyl 1,2-cyclic phosphate phosphodiesteraseUniProtKB:P16692 | has_cofactor The zinc site is remote from the catalytic metal center and was assigned a structural role. Zinc gave poor activity in the catalytic metal-substitution assay; this is not a claim that Zn2+ substitutes equivalently for catalytic manganese. | zinc(2+)CHEBI:29105 |
|
PhnG/H/I/L-dependent ribosyl triphosphate transfer to methylphosphonateRHEA:34680 | part_of Manual reaction correspondence combines matching native transformation/EC, protein catalytic annotation, and exact Rhea sides. PathBank supplies no native Rhea cross-reference. | PathBank:SMP0002077 |
|
PhnM hydrolysis of ribosyl methylphosphonate triphosphateRHEA:34684 | part_of Manual reaction correspondence combines matching native transformation/EC, protein catalytic annotation, and exact Rhea sides. PathBank supplies no native Rhea cross-reference. | PathBank:SMP0002077 |
|
PhnJ C-P cleavage with radical-SAM activation chemistryRHEA:34708 | part_of Manual reaction correspondence combines matching native transformation/EC, protein catalytic annotation, and exact Rhea sides. PathBank supplies no native Rhea cross-reference. PhnJ’s Rhea equation additionally includes the radical-activation reagents and products absent from the native minimal equation. | PathBank:SMP0002077 |
|
PhnP hydrolysis of ribosyl 1,2-cyclic phosphateRHEA:34796 | part_of Manual reaction correspondence combines matching native transformation/EC, protein catalytic annotation, and exact Rhea sides. PathBank supplies no native Rhea cross-reference. | PathBank:SMP0002077 |
|
PhnG/H/I/L-dependent ribosyl triphosphate transfer to methylphosphonateRHEA:34680 | provides_input_for Material transfer through the identified ribose intermediate establishes the reaction sequence. Native pathwayOrder contains membership links, not nextStep ordering assertions. | PhnM hydrolysis of ribosyl methylphosphonate triphosphateRHEA:34684 |
|
PhnM hydrolysis of ribosyl methylphosphonate triphosphateRHEA:34684 | provides_input_for Material transfer through the identified ribose intermediate establishes the reaction sequence. Native pathwayOrder contains membership links, not nextStep ordering assertions. | PhnJ C-P cleavage with radical-SAM activation chemistryRHEA:34708 |
|
PhnJ C-P cleavage with radical-SAM activation chemistryRHEA:34708 | provides_input_for Material transfer through the identified ribose intermediate establishes the reaction sequence. Native pathwayOrder contains membership links, not nextStep ordering assertions. | PhnP hydrolysis of ribosyl 1,2-cyclic phosphateRHEA:34796 |
|
References
PathBank:SMP0002077PathBank Methylphosphonate Degradation I, native BioPAX member PW002065.owl (source version: primary archive Last-Modified 2019-08-16; member PW002065.owl)RHEA:34680Rhea 34680 directed methylphosphonate pathway reaction (source version: 142 (2026-09-02))RHEA:34684Rhea 34684 directed methylphosphonate pathway reaction (source version: 142 (2026-09-02))RHEA:34708Rhea 34708 directed methylphosphonate pathway reaction (source version: 142 (2026-09-02))RHEA:34796Rhea 34796 directed methylphosphonate pathway reaction (source version: 142 (2026-09-02))UniProtKB:P16685UniProtKB P16685, Escherichia coli K-12 (source version: 2026_03)UniProtKB:P16686UniProtKB P16686, Escherichia coli K-12 (source version: 2026_03)UniProtKB:P16687UniProtKB P16687, Escherichia coli K-12 (source version: 2026_03)UniProtKB:P16679UniProtKB P16679, Escherichia coli K-12 (source version: 2026_03)UniProtKB:P16689UniProtKB P16689, Escherichia coli K-12 (source version: 2026_03)UniProtKB:P16688UniProtKB P16688, Escherichia coli K-12 (source version: 2026_03)UniProtKB:P16692UniProtKB P16692, Escherichia coli K-12 (source version: 2026_03)PMID:22089136Intermediates in the transformation of phosphonates to phosphate by bacteria.PMID:21341651Physiological role of phnP-specified phosphoribosyl cyclic phosphodiesterase in catabolism of organophosphonic acids by the carbon-phosphorus lyase pathway.PMID:19366688Structure of PhnP, a phosphodiesterase of the carbon-phosphorus lyase pathway for phosphonate degradation.PMID:26280334Structural insights into the bacterial carbon-phosphorus lyase machinery.PMID:36813778Structural remodelling of the carbon-phosphorus lyase machinery by a dual ABC ATPase.PMID:15342581Reversible phase variation in the phnE gene, which is required for phosphonate metabolism in Escherichia coli K-12.
Curation history
- Codex
- CREATE — Add the experimentally reconstructed E. coli methylphosphonate route
Created PathBank:SMP0002077 with four exact directed Rhea reactions, the native PhnG/H/I/L assembly, seven verified UniProt gene products and forty evidence-backed edges ending at ribose 1,5-bisphosphate. Inspected native PathBank BioPAX, UniProt, Rhea and ChEBI plus primary 2011, 2015 and 2023 full text and PhnP experimental abstracts. Retained protonation-aware cross references, radical activation scope, structural versus catalytic metals and phnE transport limitations. Duplicate searches included hidden and ignored files. Adversarial review identified unsupported free-magnesium cofactor edge031; removed it and its unused node under issue317 while preserving MgATP as the documented condition of edge027. No magnesium-independence claim is made. Source receipts, projections and exclusions are in research/pathway_additions/2026-10-10-frl-phn.
- CREATE — Add the experimentally reconstructed E. coli methylphosphonate route