eno

Summary: Enolase functions as a homo-oligomer; the phosphopyruvate hydratase complex is the multimeric enolase assembly in which catalysis occurs.

Reason: This cellular component is the standard, well-supported assignment for a member of the enolase family. Bacterial enolases form catalytically active oligomers (typically dimers/octamers), and the InterPro-based assignment of the phosphopyruvate hydratase complex is consistent with the conserved family architecture. Correct for the core function of this gene.

Summary: Enolase is an obligately Mg2+-dependent enzyme; the catalytic site coordinates Mg2+ ions required for the dehydration reaction.

Reason: UniProt/HAMAP annotates Mg2+ as the required cofactor and lists multiple Mg2+-binding residues (positions 246, 289, 316), with a second Mg2+ recruited via substrate during catalysis. Magnesium ion binding is a genuine, core molecular function of enolase.

Summary: Core catalytic activity of enolase, EC 4.2.1.11, catalyzing the reversible 2-phosphoglycerate to phosphoenolpyruvate + H2O reaction.

Reason: This is the defining molecular function of the gene product, supported by EC 4.2.1.11, RHEA:10164, conserved active-site residues (proton donor 209, proton acceptor 341) and substrate-binding residues, and the HAMAP family assignment. Represents the primary core function.

Summary: This localization derives from a UniProt subcellular-location keyword ("Secreted") propagated by the HAMAP enolase rule, which captures the moonlighting surface/secreted behavior documented in pathogens, not in P. putida KT2440.

Reason: The HAMAP rule MF_00318 attaches Secreted/Cell surface locations to all family members because enolase moonlights as a surface plasminogen-binding protein in numerous pathogens. There is no experimental evidence that the P. putida KT2440 enolase is secreted or extracellular. Three independent lines now support this beyond the original argument from absence. First, positive sequence evidence: P. putida enolase lacks both described plasminogen-binding determinants - the pneumococcal internal motif is degenerate at 3/10 identity and lysine-depleted, and the C-terminus is RAEFRG with no lysine at all, against S. pneumoniae and S. aureus controls that retain theirs. Second, a cross-ortholog GO audit shows every enolase checked - P. putida, E. coli, Listeria, Synechocystis, S. pneumoniae and S. aureus - carries GO:0005576 as a rule-derived IEA with no organism-specific input: five of the six from GO_REF:0000044, and the Listeria innocua enolase P64075 from GO_REF:0000120. A term applied uniformly across six genera regardless of whether surface display is real in that organism carries no organism-specific information, so it cannot be evidence about P. putida. Third, a blinded OpenScientist run that was not shown either analysis independently recovered the absent C-terminal lysine. Note that E. coli enolase does carry an experimental GO:0005576 (PMID:15003462), from a study reporting that a significant fraction of E. coli enolase is exported into the medium and that export tracks 2-phosphoglycerate automodification of Lys341; so non-classical enolase export is a live question. The claim made here is organism-specific and is not that bacterial enolases are never exported.

Summary: Enolase carries out its catalytic role as a cytoplasmic central-carbon metabolism enzyme.

Reason: Cytoplasm is the well-supported primary location for bacterial enolase and is consistent with its role in cytosolic glycolysis/gluconeogenesis. This is the correct localization for the core function in KT2440.

Summary: Enolase catalyzes step 4 of 5 in the glycolytic conversion of glyceraldehyde-3-phosphate to pyruvate (2-PG to PEP).

Reason: This is the canonical biological process for enolase, supported by the UniPathway glycolysis assignment (UPA00109; pyruvate from D-glyceraldehyde 3-phosphate, step 4/5) and conserved across the enolase family. Represents a core process for the gene. In KT2440 the same enzyme also operates in gluconeogenesis; a gluconeogenesis term could additionally be proposed, but the glycolytic-process annotation is correct as stated.

Summary: Cell-surface localization is propagated from the HAMAP enolase rule, reflecting moonlighting surface display in pathogens; it is not demonstrated for P. putida KT2440.

Reason: As with the extracellular-region annotation, the cell-surface location stems from UniProt/HAMAP capturing the well-documented surface plasminogen- binding moonlighting role of enolase in pathogenic bacteria (e.g. Streptococcus suis). No surfaceome or moonlighting evidence exists for the non-pathogenic soil bacterium KT2440, and the deep research advises keeping its annotation primarily cytosolic. This is an over-annotation by electronic propagation of a pathogen-specific accessory function.