conversion of succinate to propanoate

MetaCyc:PWY0-43

The Sbm/ScpABC three-enzyme biochemical cycle annotated for Escherichia coli K-12 MG1655 couples succinyl-CoA rearrangement, methylmalonyl-CoA decarboxylation and CoA transfer to succinate. Adenosylcobalamin supports Sbm mutase activity. Recombinant enzyme assays support the proposed cycle, but do not establish wild-type pathway flux. The graph retains the current reviewed Rhea/UniProt assignment of (R)-methylmalonyl-CoA to ScpB as an annotation with unresolved experimental stereospecificity: the original coupled assay did not resolve the methylmalonyl-CoA enantiomers, while later engineered strains required a heterologous epimerase for propionate production from glucose in minimal medium. A later direct ScpB assay used an R/S substrate mixture and also observed hydrolysis. These findings remain a source conflict; no unverified native epimerase is added. The native Sbm dimer and ScpB hexamer are represented as assemblies; apo-Sbm can also occur as a monomer.

Pathway type

proposed succinate decarboxylation cycle

Organism scope

Escherichia coli str. K-12 substr. MG1655 NCBITaxon:511145

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Pathway network

17 nodes · 22 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

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Components and activities

Declared biological components and source reaction directions
Node	Kind or role	Source direction
Escherichia coli str. K-12 substr. MG1655 `NCBITaxon:511145`	taxon
succinate(2-) `CHEBI:30031`	small molecule
succinyl-CoA(5-) `CHEBI:57292`	small molecule
(R)-methylmalonyl-CoA(5-) `CHEBI:57326`	small molecule
propionyl-CoA(4-) `CHEBI:57392`	small molecule
propionate `CHEBI:17272`	small molecule
hydron `CHEBI:15378`	small molecule
carbon dioxide `CHEBI:16526`	small molecule
cobamamide `CHEBI:18408`	cofactor
Methylmalonyl-CoA mutase `UniProtKB:P27253`	protein
Methylmalonyl-CoA decarboxylase `UniProtKB:P52045`	protein
Propanoyl-CoA:succinate CoA transferase `UniProtKB:P52043`	protein
methylmalonyl-CoA mutase `MetaCyc:CPLX0-7741`	complex
methylmalonyl-CoA decarboxylase `MetaCyc:CPLX0-254`	complex
succinyl-CoA => (R)-methylmalonyl-CoA `RHEA:22890`	molecular activity	right to left
(R)-methylmalonyl-CoA + H(+) => propanoyl-CoA + CO2 `RHEA:27667`	molecular activity	left to right
propanoyl-CoA + succinate => propanoate + succinyl-CoA `RHEA:28011`	molecular activity	left to right

Mechanistic edges

Mechanistic edges and their cited evidence
Subject	Predicate and description	Object	Evidence
succinyl-CoA(5-) `CHEBI:57292`	consumes	succinyl-CoA => (R)-methylmalonyl-CoA `RHEA:22890`	RHEA:22890 Source assertion: Rhea RHEA:22890 assigns CHEBI:57292 to its substrates, with coefficient 1 in rh:contains1. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/22890']/rh:substrates; rdf:Description[@rdf:about='http://rdf.rhea-db.org/22888_R']/rh:contains1[@rdf:resource='http://rdf.rhea-db.org/Participant_22888_compound_4684']; rh:compound/rh:chebi`
succinyl-CoA => (R)-methylmalonyl-CoA `RHEA:22890`	produces	(R)-methylmalonyl-CoA(5-) `CHEBI:57326`	RHEA:22890 Source assertion: Rhea RHEA:22890 assigns CHEBI:57326 to its products, with coefficient 1 in rh:contains1. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/22890']/rh:products; rdf:Description[@rdf:about='http://rdf.rhea-db.org/22888_L']/rh:contains1[@rdf:resource='http://rdf.rhea-db.org/Participant_22888_compound_1391']; rh:compound/rh:chebi`
(R)-methylmalonyl-CoA(5-) `CHEBI:57326`	consumes This is the current Rhea/UniProt (R)-specific annotation, not an enantiomer-resolved ScpB assay. PMID:28716098 reports epimerase dependence in engineered glucose/minimal-medium cultures. The conflict with the original coupled assay remains unresolved; no wild-type flux is asserted.	(R)-methylmalonyl-CoA + H(+) => propanoyl-CoA + CO2 `RHEA:27667`	RHEA:27667 Source assertion: Rhea RHEA:27667 assigns CHEBI:57326 to its substrates, with coefficient 1 in rh:contains1. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/27667']/rh:substrates; rdf:Description[@rdf:about='http://rdf.rhea-db.org/27666_L']/rh:contains1[@rdf:resource='http://rdf.rhea-db.org/Participant_27666_compound_1391']; rh:compound/rh:chebi`
hydron `CHEBI:15378`	consumes This is the current Rhea/UniProt (R)-specific annotation, not an enantiomer-resolved ScpB assay. PMID:28716098 reports epimerase dependence in engineered glucose/minimal-medium cultures. The conflict with the original coupled assay remains unresolved; no wild-type flux is asserted.	(R)-methylmalonyl-CoA + H(+) => propanoyl-CoA + CO2 `RHEA:27667`	RHEA:27667 Source assertion: Rhea RHEA:27667 assigns CHEBI:15378 to its substrates, with coefficient 1 in rh:contains1. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/27667']/rh:substrates; rdf:Description[@rdf:about='http://rdf.rhea-db.org/27666_L']/rh:contains1[@rdf:resource='http://rdf.rhea-db.org/Participant_27666_compound_3249']; rh:compound/rh:chebi`
(R)-methylmalonyl-CoA + H(+) => propanoyl-CoA + CO2 `RHEA:27667`	produces This is the current Rhea/UniProt (R)-specific annotation, not an enantiomer-resolved ScpB assay. PMID:28716098 reports epimerase dependence in engineered glucose/minimal-medium cultures. The conflict with the original coupled assay remains unresolved; no wild-type flux is asserted.	propionyl-CoA(4-) `CHEBI:57392`	RHEA:27667 Source assertion: Rhea RHEA:27667 assigns CHEBI:57392 to its products, with coefficient 1 in rh:contains1. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/27667']/rh:products; rdf:Description[@rdf:about='http://rdf.rhea-db.org/27666_R']/rh:contains1[@rdf:resource='http://rdf.rhea-db.org/Participant_27666_compound_3421']; rh:compound/rh:chebi`
(R)-methylmalonyl-CoA + H(+) => propanoyl-CoA + CO2 `RHEA:27667`	produces This is the current Rhea/UniProt (R)-specific annotation, not an enantiomer-resolved ScpB assay. PMID:28716098 reports epimerase dependence in engineered glucose/minimal-medium cultures. The conflict with the original coupled assay remains unresolved; no wild-type flux is asserted.	carbon dioxide `CHEBI:16526`	RHEA:27667 Source assertion: Rhea RHEA:27667 assigns CHEBI:16526 to its products, with coefficient 1 in rh:contains1. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/27667']/rh:products; rdf:Description[@rdf:about='http://rdf.rhea-db.org/27666_R']/rh:contains1[@rdf:resource='http://rdf.rhea-db.org/Participant_27666_compound_4391']; rh:compound/rh:chebi`
propionyl-CoA(4-) `CHEBI:57392`	consumes	propanoyl-CoA + succinate => propanoate + succinyl-CoA `RHEA:28011`	RHEA:28011 Source assertion: Rhea RHEA:28011 assigns CHEBI:57392 to its substrates, with coefficient 1 in rh:contains1. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/28011']/rh:substrates; rdf:Description[@rdf:about='http://rdf.rhea-db.org/28010_L']/rh:contains1[@rdf:resource='http://rdf.rhea-db.org/Participant_28010_compound_3421']; rh:compound/rh:chebi`
succinate(2-) `CHEBI:30031`	consumes	propanoyl-CoA + succinate => propanoate + succinyl-CoA `RHEA:28011`	RHEA:28011 Source assertion: Rhea RHEA:28011 assigns CHEBI:30031 to its substrates, with coefficient 1 in rh:contains1. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/28011']/rh:substrates; rdf:Description[@rdf:about='http://rdf.rhea-db.org/28010_L']/rh:contains1[@rdf:resource='http://rdf.rhea-db.org/Participant_28010_compound_2501']; rh:compound/rh:chebi`
propanoyl-CoA + succinate => propanoate + succinyl-CoA `RHEA:28011`	produces	propionate `CHEBI:17272`	RHEA:28011 Source assertion: Rhea RHEA:28011 assigns CHEBI:17272 to its products, with coefficient 1 in rh:contains1. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/28011']/rh:products; rdf:Description[@rdf:about='http://rdf.rhea-db.org/28010_R']/rh:contains1[@rdf:resource='http://rdf.rhea-db.org/Participant_28010_compound_4801']; rh:compound/rh:chebi`
propanoyl-CoA + succinate => propanoate + succinyl-CoA `RHEA:28011`	produces	succinyl-CoA(5-) `CHEBI:57292`	RHEA:28011 Source assertion: Rhea RHEA:28011 assigns CHEBI:57292 to its products, with coefficient 1 in rh:contains1. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/28011']/rh:products; rdf:Description[@rdf:about='http://rdf.rhea-db.org/28010_R']/rh:contains1[@rdf:resource='http://rdf.rhea-db.org/Participant_28010_compound_4684']; rh:compound/rh:chebi`
Methylmalonyl-CoA mutase `UniProtKB:P27253`	part_of Membership represents the annotated Sbm homodimer; it does not imply that all apo-Sbm is dimeric or include the distinct YgfD-bound assembly.	methylmalonyl-CoA mutase `MetaCyc:CPLX0-7741`	MetaCyc:CPLX0-7741 Source assertion: MetaCyc CPLX0-7741 contains 2 copies of METHYLMALONYL-COA-MUT-MONOMER and assigns the assembly to E. coli K-12 MG1655. Source location `Protein[@frameid='CPLX0-7741']/component; species/Organism[@frameid='TAX-511145']` MetaCyc:METHYLMALONYL-COA-MUT-MONOMER Source assertion: The native METHYLMALONYL-COA-MUT-MONOMER protein has a UniProt unification cross-reference to P27253. Source location `Protein[@frameid='METHYLMALONYL-COA-MUT-MONOMER']/dblink[dblink-db='UNIPROT']/dblink-oid` PMID:18950999 Source assertion: Native PAGE and size exclusion detected apo-Sbm as a mixture of monomer and dimer. Source location `Results, Interaction of YgfD and Sbm in vitro (P17); Figure 4B and Figure 4C, panel 2; Discussion`
Methylmalonyl-CoA decarboxylase `UniProtKB:P52045`	part_of	methylmalonyl-CoA decarboxylase `MetaCyc:CPLX0-254`	MetaCyc:CPLX0-254 Source assertion: MetaCyc CPLX0-254 contains 6 copies of G7516-MONOMER and assigns the assembly to E. coli K-12 MG1655. Source location `Protein[@frameid='CPLX0-254']/component; species/Organism[@frameid='TAX-511145']` MetaCyc:G7516-MONOMER Source assertion: The native G7516-MONOMER protein has a UniProt unification cross-reference to P52045. Source location `Protein[@frameid='G7516-MONOMER']/dblink[dblink-db='UNIPROT']/dblink-oid` PMID:10769118 Source assertion: The E. coli decarboxylase crystal structure forms a hexamer arranged as two trimers. Source location `Indexed abstract; oligomeric architecture`
methylmalonyl-CoA mutase `MetaCyc:CPLX0-7741`	catalyzes RHEA:22890 selects the succinyl-CoA-to-(R)-methylmalonyl-CoA direction of the reversible mutase reaction for the proposed cycle.	succinyl-CoA => (R)-methylmalonyl-CoA `RHEA:22890`	MetaCyc:CPLX0-7741 Source assertion: MetaCyc CPLX0-7741 is the enzyme assigned to METHYLMALONYL-COA-MUT-RXN. Source location `Protein[@frameid='CPLX0-7741']/catalyzes/Enzymatic-Reaction/reaction` UniProtKB:P27253 Source assertion: Reviewed UniProt P27253 assigns (R)-methylmalonyl-CoA = succinyl-CoA (RHEA:22888; ECO:0000269, PMID:10769117). Source location `comments[commentType='CATALYTIC ACTIVITY'].reaction` PMID:10769117 Source assertion: Adenosylcobalamin-reconstituted Sbm converted succinyl-CoA to propionyl-CoA in a coupled assay containing excess YgfG/ScpB. Source location `pp. 4624-4625, Reconstitution and HPLC Assay of Sbm; p. 4627, Function of Sbm`
methylmalonyl-CoA decarboxylase `MetaCyc:CPLX0-254`	catalyzes This is the current Rhea/UniProt (R)-specific annotation, not an enantiomer-resolved ScpB assay. PMID:28716098 reports epimerase dependence in engineered glucose/minimal-medium cultures. The conflict with the original coupled assay remains unresolved; no wild-type flux is asserted. The 2019 assay used an R/S substrate mixture.	(R)-methylmalonyl-CoA + H(+) => propanoyl-CoA + CO2 `RHEA:27667`	MetaCyc:CPLX0-254 Source assertion: MetaCyc CPLX0-254 is the enzyme assigned to RXN0-310. Source location `Protein[@frameid='CPLX0-254']/catalyzes/Enzymatic-Reaction/reaction` UniProtKB:P52045 Source assertion: Reviewed UniProt P52045 assigns (R)-methylmalonyl-CoA + H(+) = propanoyl-CoA + CO2 (RHEA:27666; ECO:0000269, PMID:10769117). Source location `comments[commentType='CATALYTIC ACTIVITY'].reaction` PMID:10769117 Source assertion: Purified YgfG/ScpB catalyzed methylmalonyl-CoA decarboxylation; coupled Sbm/YgfG assays converted succinyl-CoA to propionyl-CoA. Source location `p. 4626, Function of YgfG and Table 1; p. 4627, Function of Sbm` PMID:28716098 Source assertion: Engineered BL21 and DH5alpha cultures required heterologous methylmalonyl-CoA epimerase for propionate production from glucose in minimal medium; the paper questions ScpB stereospecificity. Source location `Results, Heterologous PA production, epimerase co-expression; Discussion` DOI:10.1021/jacs.9b00650.s001 Source assertion: The 2019 MMCD-His6 assay used (R/S)-methylmalonyl-CoA and measured propionyl-CoA and free CoA. It supports decarboxylation plus hydrolysis without resolving ScpB enantiomer specificity. Source location `Supporting Information, Section VIII pp. S14-S15; Figures S4-S5 pp. S27-S28`
Propanoyl-CoA:succinate CoA transferase `UniProtKB:P52043`	catalyzes RHEA:28011 selects the propionyl-CoA plus succinate direction of a reversible CoA transferase reaction; ScpC is represented by its protein identifier without an unsupported oligomeric state.	propanoyl-CoA + succinate => propanoate + succinyl-CoA `RHEA:28011`	MetaCyc:G7517-MONOMER Source assertion: MetaCyc G7517-MONOMER is the enzyme assigned to RXN0-268. Source location `Protein[@frameid='G7517-MONOMER']/catalyzes/Enzymatic-Reaction/reaction` UniProtKB:P52043 Source assertion: Reviewed UniProt P52043 assigns propanoyl-CoA + succinate = propanoate + succinyl-CoA (RHEA:28010; ECO:0000269, PMID:10769117). Source location `comments[commentType='CATALYTIC ACTIVITY'].reaction` PMID:10769117 Source assertion: Purified YgfH/ScpC transferred CoA from propionyl-CoA to succinate in an HPLC assay. Source location `p. 4624, HPLC Assay of YgfH; p. 4627, Function of YgfH`
Methylmalonyl-CoA mutase `UniProtKB:P27253`	has_cofactor CHEBI:18408 has canonical ChEBI label cobamamide; this is adenosylcobalamin, not a generic vitamin B12 pool or a consumed pathway substrate.	cobamamide `CHEBI:18408`	UniProtKB:P27253 Source assertion: Reviewed UniProt P27253 assigns adenosylcob(III)alamin (CHEBI:18408) as cofactor with ECO:0000269 citing PMID:10769117 and PMID:11955068. Source location `comments[commentType='COFACTOR'].cofactors` PMID:10769117 Source assertion: Recombinant apo-Sbm was reconstituted with adenosylcobalamin before the mutase assay. Source location `p. 4624, Reconstitution and HPLC Assay of Sbm; p. 4627, Function of Sbm`
succinyl-CoA => (R)-methylmalonyl-CoA `RHEA:22890`	part_of Membership in the experimentally motivated biochemical proposal does not assert operation of a complete native cycle under unspecified growth conditions.	`MetaCyc:PWY0-43`	MetaCyc:PWY0-43 Source assertion: MetaCyc PWY0-43 lists METHYLMALONYL-COA-MUT-RXN in its three-reaction proposed succinate-to-propanoate cycle; its comment states that a metabolic role has not been shown. Source location `Pathway[@frameid='PWY0-43']/reaction-list/Reaction[@frameid='METHYLMALONYL-COA-MUT-RXN']; comment` MetaCyc:METHYLMALONYL-COA-MUT-RXN Source assertion: The native reaction METHYLMALONYL-COA-MUT-RXN has the chemical sides and Rhea cross-reference corresponding to this selected directional reaction. Source location `Reaction[@frameid='METHYLMALONYL-COA-MUT-RXN']/left; right; reaction-direction; dblink[dblink-db='RHEA']`
(R)-methylmalonyl-CoA + H(+) => propanoyl-CoA + CO2 `RHEA:27667`	part_of Membership in the experimentally motivated biochemical proposal does not assert operation of a complete native cycle under unspecified growth conditions.	`MetaCyc:PWY0-43`	MetaCyc:PWY0-43 Source assertion: MetaCyc PWY0-43 lists RXN0-310 in its three-reaction proposed succinate-to-propanoate cycle; its comment states that a metabolic role has not been shown. Source location `Pathway[@frameid='PWY0-43']/reaction-list/Reaction[@frameid='RXN0-310']; comment` MetaCyc:RXN0-310 Source assertion: The native reaction RXN0-310 has the chemical sides and Rhea cross-reference corresponding to this selected directional reaction. Source location `Reaction[@frameid='RXN0-310']/left; right; reaction-direction; dblink[dblink-db='RHEA']`
propanoyl-CoA + succinate => propanoate + succinyl-CoA `RHEA:28011`	part_of Membership in the experimentally motivated biochemical proposal does not assert operation of a complete native cycle under unspecified growth conditions.	`MetaCyc:PWY0-43`	MetaCyc:PWY0-43 Source assertion: MetaCyc PWY0-43 lists RXN0-268 in its three-reaction proposed succinate-to-propanoate cycle; its comment states that a metabolic role has not been shown. Source location `Pathway[@frameid='PWY0-43']/reaction-list/Reaction[@frameid='RXN0-268']; comment` MetaCyc:RXN0-268 Source assertion: The native reaction RXN0-268 has the chemical sides and Rhea cross-reference corresponding to this selected directional reaction. Source location `Reaction[@frameid='RXN0-268']/left; right; reaction-direction; dblink[dblink-db='RHEA']`
succinyl-CoA => (R)-methylmalonyl-CoA `RHEA:22890`	provides_input_for This is the current Rhea/UniProt (R)-specific annotation, not an enantiomer-resolved ScpB assay. PMID:28716098 reports epimerase dependence in engineered glucose/minimal-medium cultures. The conflict with the original coupled assay remains unresolved; no wild-type flux is asserted.	(R)-methylmalonyl-CoA + H(+) => propanoyl-CoA + CO2 `RHEA:27667`	MetaCyc:PWY0-43 Source assertion: Native PWY0-43 reaction order places METHYLMALONYL-COA-MUT-RXN before RXN0-310 in the proposed cycle, sharing (R)-methylmalonyl-CoA. Source location `Pathway[@frameid='PWY0-43']/reaction-ordering[Reaction[@frameid='RXN0-310'] and predecessor-reactions/Reaction[@frameid='METHYLMALONYL-COA-MUT-RXN']]; reaction-layout`
(R)-methylmalonyl-CoA + H(+) => propanoyl-CoA + CO2 `RHEA:27667`	provides_input_for This edge records the native biochemical-cycle layout, not measured wild-type flux or an additional physiological inference.	propanoyl-CoA + succinate => propanoate + succinyl-CoA `RHEA:28011`	MetaCyc:PWY0-43 Source assertion: Native PWY0-43 reaction order places RXN0-310 before RXN0-268 in the proposed cycle, sharing propionyl-CoA. Source location `Pathway[@frameid='PWY0-43']/reaction-ordering[Reaction[@frameid='RXN0-268'] and predecessor-reactions/Reaction[@frameid='RXN0-310']]; reaction-layout`
propanoyl-CoA + succinate => propanoate + succinyl-CoA `RHEA:28011`	provides_input_for This edge records the native biochemical-cycle layout, not measured wild-type flux or an additional physiological inference.	succinyl-CoA => (R)-methylmalonyl-CoA `RHEA:22890`	MetaCyc:PWY0-43 Source assertion: Native PWY0-43 reaction order places RXN0-268 before METHYLMALONYL-COA-MUT-RXN in the proposed cycle, sharing succinyl-CoA. Source location `Pathway[@frameid='PWY0-43']/reaction-ordering[Reaction[@frameid='METHYLMALONYL-COA-MUT-RXN'] and predecessor-reactions/Reaction[@frameid='RXN0-268']]; reaction-layout`

References

MetaCyc:PWY0-43 MetaCyc PWY0-43 (source version: 22.5; official mirror retrieved 2026-10-10)
MetaCyc:CPLX0-7741 MetaCyc CPLX0-7741 (source version: 22.5; official mirror retrieved 2026-10-10)
MetaCyc:CPLX0-254 MetaCyc CPLX0-254 (source version: 22.5; official mirror retrieved 2026-10-10)
MetaCyc:METHYLMALONYL-COA-MUT-MONOMER MetaCyc METHYLMALONYL-COA-MUT-MONOMER (source version: 22.5; official mirror retrieved 2026-10-10)
MetaCyc:G7516-MONOMER MetaCyc G7516-MONOMER (source version: 22.5; official mirror retrieved 2026-10-10)
MetaCyc:G7517-MONOMER MetaCyc G7517-MONOMER (source version: 22.5; official mirror retrieved 2026-10-10)
MetaCyc:METHYLMALONYL-COA-MUT-RXN MetaCyc METHYLMALONYL-COA-MUT-RXN (source version: 22.5; official mirror retrieved 2026-10-10)
MetaCyc:RXN0-310 MetaCyc RXN0-310 (source version: 22.5; official mirror retrieved 2026-10-10)
MetaCyc:RXN0-268 MetaCyc RXN0-268 (source version: 22.5; official mirror retrieved 2026-10-10)
UniProtKB:P27253 Reviewed UniProtKB P27253 (source version: 2026_03; retrieved 2026-10-10)
UniProtKB:P52045 Reviewed UniProtKB P52045 (source version: 2026_03; retrieved 2026-10-10)
UniProtKB:P52043 Reviewed UniProtKB P52043 (source version: 2026_03; retrieved 2026-10-10)
RHEA:22890 Rhea 22890 directional reaction (source version: 142 (2026-09-02))
RHEA:27667 Rhea 27667 directional reaction (source version: 142 (2026-09-02))
RHEA:28011 Rhea 28011 directional reaction (source version: 142 (2026-09-02))
PMID:10769117 Discovering new enzymes and metabolic pathways: conversion of succinate to propionate by Escherichia coli. (source version: Primary full text; DOI 10.1021/bi992888d; retrieved 2026-10-10)
PMID:18950999 Sleeping beauty mutase (sbm) is expressed and interacts with ygfD in Escherichia coli. (source version: Primary full text; retrieved 2026-10-10)
PMID:10769118 New reactions in the crotonase superfamily: structure of methylmalonyl CoA decarboxylase from Escherichia coli. (source version: Europe PMC core metadata and complete indexed abstract; retrieved 2026-10-10)
PMID:28716098 Awakening sleeping beauty: production of propionic acid in Escherichia coli through the sbm operon requires the activity of a methylmalonyl-CoA epimerase. (source version: Primary full text; retrieved 2026-10-10)
DOI:10.1021/jacs.9b00650.s001 Supporting Information: Sulfonate/Nitro Bearing Methylmalonyl-Thioester Isosteres Applied to Methylmalonyl-CoA Decarboxylase Structure-Function Studies. (source version: ACS Figshare article 7863569, file 14641211; retrieved 2026-10-10)

Curation history

2026-10-10T23:04:36Z codex
- CREATE — Add the proposed Sbm/ScpABC cycle with explicit stereochemistry and physiological limits
  Curated MetaCyc:PWY0-43 using native MetaCyc, reviewed UniProt, directed Rhea and inspected primary studies including the 2019 supporting information. Retains three reactions, two native assemblies, adenosylcobalamin and 22 edges with 38 evidence blocks. Native/closed schema, independently verified identities, ten Rhea chemical edges, elemental/charge balance, net chemistry and twenty reference hashes passed author checks. Independent review found an incorrect apo-Sbm source locator; issue324 corrects it to Results Interaction of YgfD and Sbm in vitro, Figure4B and Figure4C panel2. R/S assay ambiguity and later engineered-strain epimerase dependence remain explicit. No native epimerase, sodium/biotin requirement or wild-type flux is asserted. Full-corpus gates, graph export verification and final independent review are documented separately.
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