trehalose biosynthesis I

MetaCyc:TRESYN-PWY

Trehalose biosynthesis I converts D-glucose 6-phosphate and UDP-alpha-D-glucose to alpha,alpha-trehalose through alpha,alpha-trehalose 6-phosphate.

Pathway type

compatible solute biosynthesis

Organism scope

Escherichia coli NCBITaxon:562

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Pathway network

18 nodes · 18 asserted directed edges

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Reaction / activity
Chemical / cofactor
Protein / complex
Other participant
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 `NCBITaxon:562`	taxon
alpha,alpha-trehalose-phosphate synthase (UDP-forming) `EC:2.4.1.15`	molecular activity
trehalose-phosphatase `EC:3.1.3.12`	molecular activity
D-glucose 6-phosphate `CHEBI:61548`	small molecule
UDP-alpha-D-glucose `CHEBI:58885`	small molecule
alpha,alpha-trehalose 6-phosphate `CHEBI:58429`	small molecule
UDP `CHEBI:58223`	small molecule
H+ `CHEBI:15378`	small molecule
H2O `CHEBI:15377`	small molecule
alpha,alpha-trehalose `CHEBI:16551`	small molecule
phosphate `CHEBI:43474`	small molecule
Trehalose-6-phosphate synthase `UniProtKB:P31677`	protein
Trehalose-6-phosphate phosphatase `UniProtKB:P31678`	protein
magnesium(2+) `CHEBI:18420`	cofactor
manganese(2+) `CHEBI:29035`	cofactor
cobalt(2+) `CHEBI:48828`	cofactor
zinc(2+) `CHEBI:29105`	cofactor
trehalose-6-phosphate synthase reaction `RHEA:18890`	reaction	left to right
trehalose-6-phosphate phosphatase reaction `RHEA:23421`	reaction	left to right

Mechanistic edges

Mechanistic edges and their cited evidence
Subject	Predicate and description	Object	Evidence
UDP-alpha-D-glucose `CHEBI:58885`	consumes	trehalose-6-phosphate synthase reaction `RHEA:18890`	RHEA:18890 Source assertion: Rhea lists CHEBI:58885 on the substrates side of RHEA:18890 in this directed reaction. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/18890']/rh:substrates; rh:contains/rh:compound/rh:accession`
D-glucose 6-phosphate `CHEBI:61548`	consumes	trehalose-6-phosphate synthase reaction `RHEA:18890`	RHEA:18890 Source assertion: Rhea lists CHEBI:61548 on the substrates side of RHEA:18890 in this directed reaction. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/18890']/rh:substrates; rh:contains/rh:compound/rh:accession`
trehalose-6-phosphate synthase reaction `RHEA:18890`	produces	H+ `CHEBI:15378`	RHEA:18890 Source assertion: Rhea lists CHEBI:15378 on the products side of RHEA:18890 in this directed reaction. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/18890']/rh:products; rh:contains/rh:compound/rh:accession`
trehalose-6-phosphate synthase reaction `RHEA:18890`	produces	UDP `CHEBI:58223`	RHEA:18890 Source assertion: Rhea lists CHEBI:58223 on the products side of RHEA:18890 in this directed reaction. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/18890']/rh:products; rh:contains/rh:compound/rh:accession`
trehalose-6-phosphate synthase reaction `RHEA:18890`	produces	alpha,alpha-trehalose 6-phosphate `CHEBI:58429`	RHEA:18890 Source assertion: Rhea lists CHEBI:58429 on the products side of RHEA:18890 in this directed reaction. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/18890']/rh:products; rh:contains/rh:compound/rh:accession`
H2O `CHEBI:15377`	consumes	trehalose-6-phosphate phosphatase reaction `RHEA:23421`	RHEA:23421 Source assertion: Rhea lists CHEBI:15377 on the substrates side of RHEA:23421 in this directed reaction. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/23421']/rh:substrates; rh:contains/rh:compound/rh:accession`
alpha,alpha-trehalose 6-phosphate `CHEBI:58429`	consumes	trehalose-6-phosphate phosphatase reaction `RHEA:23421`	RHEA:23421 Source assertion: Rhea lists CHEBI:58429 on the substrates side of RHEA:23421 in this directed reaction. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/23421']/rh:substrates; rh:contains/rh:compound/rh:accession`
trehalose-6-phosphate phosphatase reaction `RHEA:23421`	produces	alpha,alpha-trehalose `CHEBI:16551`	RHEA:23421 Source assertion: Rhea lists CHEBI:16551 on the products side of RHEA:23421 in this directed reaction. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/23421']/rh:products; rh:contains/rh:compound/rh:accession`
trehalose-6-phosphate phosphatase reaction `RHEA:23421`	produces	phosphate `CHEBI:43474`	RHEA:23421 Source assertion: Rhea lists CHEBI:43474 on the products side of RHEA:23421 in this directed reaction. Source location `rdf:Description[@rdf:about='http://rdf.rhea-db.org/23421']/rh:products; rh:contains/rh:compound/rh:accession`
alpha,alpha-trehalose-phosphate synthase (UDP-forming) `EC:2.4.1.15`	catalyzes	trehalose-6-phosphate synthase reaction `RHEA:18890`	RHEA:18889 Source assertion: Rhea associates EC:2.4.1.15 with the reaction family containing RHEA:18890. Source location `rh:ec` PMID:8045430 The Escherichia coli otsBA operon, located at min 42, was sequenced and shown to encode a 29.1-kDa trehalose-6-phosphate phosphatase (OtsB) and a 53.6-kDa trehalose-6-phosphate synthase (OtsA). Source location `PubMed Abstract`
trehalose-phosphatase `EC:3.1.3.12`	catalyzes	trehalose-6-phosphate phosphatase reaction `RHEA:23421`	RHEA:23420 Source assertion: Rhea associates EC:3.1.3.12 with the reaction family containing RHEA:23421. Source location `rh:ec` PMID:8045430 The Escherichia coli otsBA operon, located at min 42, was sequenced and shown to encode a 29.1-kDa trehalose-6-phosphate phosphatase (OtsB) and a 53.6-kDa trehalose-6-phosphate synthase (OtsA). Source location `PubMed Abstract`
trehalose-6-phosphate synthase reaction `RHEA:18890`	precedes	trehalose-6-phosphate phosphatase reaction `RHEA:23421`	MetaCyc:TRESYN-PWY Source assertion: MetaCyc pathway ordering places RHEA:18890 before RHEA:23421 in this pathway. Shared intermediate: CHEBI:58429. Source location `Pathway/reaction-ordering and reaction-layout; Rhea-to-MetaCyc cross-references`
Trehalose-6-phosphate synthase `UniProtKB:P31677`	enables	trehalose-6-phosphate synthase reaction `RHEA:18890`	UniProtKB:P31677 Source assertion: UniProt annotates UniProtKB:P31677 with catalytic activity for the reaction family of RHEA:18890. Annotation evidence: ECO:0000305; organism taxon: NCBITaxon:83333. Source location `comments[commentType='CATALYTIC ACTIVITY'].reaction.reactionCrossReferences`
Trehalose-6-phosphate phosphatase `UniProtKB:P31678`	enables	trehalose-6-phosphate phosphatase reaction `RHEA:23421`	UniProtKB:P31678 Source assertion: UniProt annotates UniProtKB:P31678 with catalytic activity for the reaction family of RHEA:23421. Annotation evidence: ECO:0000269; organism taxon: NCBITaxon:83333. Source location `comments[commentType='CATALYTIC ACTIVITY'].reaction.reactionCrossReferences`
Trehalose-6-phosphate phosphatase `UniProtKB:P31678`	has_cofactor	magnesium(2+) `CHEBI:18420`	UniProtKB:P31678 Source assertion: UniProt lists CHEBI:18420 as a cofactor of UniProtKB:P31678 (evidence: ECO:0000269). Magnesium. Can also use other divalent metal cations as manganese, cobalt or zinc. Source location `comments[commentType='COFACTOR'].cofactors and note`
Trehalose-6-phosphate phosphatase `UniProtKB:P31678`	has_cofactor	manganese(2+) `CHEBI:29035`	UniProtKB:P31678 Source assertion: UniProt lists CHEBI:29035 as a cofactor of UniProtKB:P31678 (evidence: ECO:0000269). Magnesium. Can also use other divalent metal cations as manganese, cobalt or zinc. Source location `comments[commentType='COFACTOR'].cofactors and note`
Trehalose-6-phosphate phosphatase `UniProtKB:P31678`	has_cofactor	cobalt(2+) `CHEBI:48828`	UniProtKB:P31678 Source assertion: UniProt lists CHEBI:48828 as a cofactor of UniProtKB:P31678 (evidence: ECO:0000269). Magnesium. Can also use other divalent metal cations as manganese, cobalt or zinc. Source location `comments[commentType='COFACTOR'].cofactors and note`
Trehalose-6-phosphate phosphatase `UniProtKB:P31678`	has_cofactor	zinc(2+) `CHEBI:29105`	UniProtKB:P31678 Source assertion: UniProt lists CHEBI:29105 as a cofactor of UniProtKB:P31678 (evidence: ECO:0000269). Magnesium. Can also use other divalent metal cations as manganese, cobalt or zinc. Source location `comments[commentType='COFACTOR'].cofactors and note`

References

MetaCyc:TRESYN-PWY MetaCyc trehalose biosynthesis I pathway (source version: 22.5)
RHEA:18889 Rhea trehalose-6-phosphate synthase reaction (source version: 139)
RHEA:18890 Rhea left-to-right trehalose-6-phosphate synthase direction (source version: 139)
RHEA:23420 Rhea trehalose-6-phosphate phosphatase reaction (source version: 139)
RHEA:23421 Rhea left-to-right trehalose-6-phosphate phosphatase direction (source version: 139)
PMID:3131312 Giaever et al., Journal of Bacteriology, 1988
PMID:8045430 Kaasen et al., Gene, 1994
UniProtKB:P31677 UniProtKB:P31677 authority record (source version: 2026_03)
UniProtKB:P31678 UniProtKB:P31678 authority record (source version: 2026_03)

Curation history

2026-10-05T06:25:52Z codex
- EDIT — Review causal chemistry and add sourced molecular context
  Reviewed the entire record against MetaCyc 22.5 native pathway XML (including nested pathways), Rhea 139 explicit sides and directions, ENZYME 02-Sep-2026, PubMed records, and reviewed UniProt 2026_03 annotations within the record's taxon scope. Replaced generated structured-source quotations with source_assertion and source_locator. Typed molecular activities and participants. Reaction count 2 to 2; 0 directed-ID corrections; 2 protein annotations, 4 cofactor annotations and 0 sourced locations. All Rhea reaction substrate/product sets checked against independent Rhea authority; native pathway leaf coverage and source exceptions recorded in reports/causal_graph_review/metacyc-review.json. Full source URLs, versions and byte hashes are in metacyc-sources.json. All 50 MetaCyc records passed native schema validation; six targeted chemistry/evidence regression tests passed. Missing protein or cofactor annotations are not treated as biological absence; qualifications and exclusions are preserved in the ledger.
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