glbO Resolved · high auto-curated

H37Rv Rv2470 · MTBC0 mtbc0_002632 · 128 aa · 2797426–2797812 (+) · RefSeq NP_216986.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hemoglobin GlbO
MTBC0 PGAP re-annotationgroup 2 truncated hemoglobin GlbO
Revised (this work)Group 2 truncated hemoglobin GlbO. Pfam: Bac_globin (PF01152.28).

Auto-curated: this verdict and function were generated by rules from PGAP + Pfam + Foldseek and have not been hand-reviewed.

Curated reference (UniProt)

UniProt P9WN23 SwissProt · reviewed · Evidence at protein level
UniProt nameGroup 2 truncated hemoglobin GlbO
Curated functionWhen expressed in E.coli and M.smegmatis, HbO increases oxygen uptake. Membrane vesicles of E.coli carrying HbO show a respiration activity about twice that of membranes without HbO. HbO seems to interact with a terminal oxidase. Therefore, HbO could participate in oxygen/electron-transfer process, suggesting a function related to the facilitation of oxygen transfer during aerobic metabolism of M.tuberculosis.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
Preferred nameglbO
eggNOG descriptiontruncated
Orthologous groupCOG2346
KEGG orthology K06886
Gene Ontology (26) GO:0003674, GO:0005488, GO:0005575, GO:0005623, GO:0005886, GO:0006810, GO:0008144, GO:0008150, GO:0015669, GO:0015671, GO:0015893, GO:0016020 +14 more

Orthology-based transfer (eggNOG 5.0.2, diamond). EC/KO/GO/CAZy are computed annotations, not manual curation; cross-check against the primary literature before treating a specific reaction as established.

Conservation & selection (intra-MTBC, 145 209 strains)

pN/pS 0.953 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 1 synonymous, 3 missense, 0 nonsense, 0 frameshift

pN/pS from segregating SNPs (singletons removed) normalised by possible sites. Low pN/pS = purifying selection (a strong signal that a "hypothetical" is a real, constrained gene). A high pN/pS is ambiguous: relaxed constraint or positive selection (drug resistance, antigenic variation) inflate it; e.g. rpoB/katG/pncA score high here for resistance, not loss of function. A clonal disruption (one allele over a clade) suggests lineage pseudogenisation; a convergent one (many independent alleles) is typical of resistance loss-of-function.

Domains (Pfam, hmmscan --cut_ga)

PfamAccessioni-EvalueResiduesDescription
Bac_globinPF01152.28 1.5e-424–121 Bacterial-like globin

Functional interaction network (STRING v12, guilt-by-association)

Closest characterised functional partner: aglA (alpha-glucosidase AglA), high confidence from genomic context alone (score 950 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2471 aglA alpha-glucosidase AglA 950 950 ctx neighborhood:881 fusion:596
Rv2469c hyp hypothetical protein 774 774 ctx neighborhood:773
Rv2472 hyp hypothetical protein 638 639 ctx neighborhood:637
Rv2473 hyp hypothetical protein 577 578 ctx neighborhood:578
Rv2468A hyp hypothetical protein 563 563 ctx neighborhood:563
Rv3283 sseA thiosulfate sulfurtransferase SseA 534 534 coexpression:533
Rv2466c hyp hypothetical protein 576 533 coexpression:419
Rv2468c hyp hypothetical protein 527 526 ctx neighborhood:526
Rv0385 monooxygenase 410 364
Rv1542c glbN hemoglobin GlbN 965 46 textmining:965
Rv3568c hsaC extradiol dioxygenase 442 46 textmining:440
Rv2674 msrB peptide methionine sulfoxide reductase MsrB 673 41 textmining:673
Rv3515c fadD19 acyl-CoA synthetase 440 41 textmining:440

STRING combines evidence channels (neighborhood, fusion, cooccurrence, coexpression, experimental, database, text-mining) into a 0–1000 score. The ctx badge marks edges carried by the genomic-context channels (conserved neighborhood, fusion, phylogenetic co-occurrence), which are independent of orthology and structure and the strongest signal for an unknown gene. The no text-mining column recomputes the score from data alone, so a link that does not depend on the literature is visible. Association is a function hypothesis, not proof: corroborate with the operon context and the primary literature before assigning a function.

Evidence

  • Legacy H37Rv annotation: hemoglobin GlbO
  • MTBC0 PGAP product: group 2 truncated hemoglobin GlbO
  • Pfam (hmmscan --cut_ga): Bac_globin PF01152.28 (E=2e-42)
  • (auto-curated by rules from PGAP + Pfam + Foldseek; not hand-reviewed)

Sources

  • Ancestral sequence & coordinates: Harrison LB et al. (2024), An imputed ancestral reference genome for the MTBC, doi:10.1101/2023.09.07.556366
  • Product annotation: NCBI PGAP on MTBC0; legacy from H37Rv NC_000962.3 (RefSeq NP_216986.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Bac_globin (PF01152.28)
  • Sequence-level signal: ESM Atlas (EvolutionaryScale × BioHub) — exploratory
  • Controlled vocabulary: eggNOG-mapper 2.1.12 (Cantalapiedra et al. 2021, doi:10.1093/molbev/msab293), eggNOG 5.0 DB (Huerta-Cepas et al. 2019) — OG COG2346
  • Curated reference: UniProt P9WN23 (SwissProt, reviewed; Evidence at protein level)
  • Intra-MTBC selection: pN/pS and disruption from SPDI variants of 145 209 MTBC strains (this work, local collection vs H37Rv NC_000962.3)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 13 functional partner(s); context anchor aglA
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_002632|Rv2470|glbO
MPKSFYDAVGGAKTFDAIVSRFYAQVAEDEVLRRVYPEDDLAGAEERLRMFLEQYWGGPRTYSEQRGHPRLRMRHAPFRISLIERDAWLRCMHTAVASIDSETLDDEHRRELLDYLEMAAHSLVNSPF