cobG Resolved · high auto-curated

H37Rv Rv2064 · MTBC0 mtbc0_002198 · 363 aa · 2350064–2351155 (+) · RefSeq NP_216580.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)precorrin-3B synthase
MTBC0 PGAP re-annotationprecorrin-3B synthase
Revised (this work)Precorrin-3B synthase. Pfam: NIR_SIR_ferr (PF03460.23).

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

Curated reference (UniProt)

UniProt Q10675 TrEMBL · unreviewed · Evidence at protein level
UniProt namePrecorrin-3B synthase CobG

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category C Energy production and conversion
Preferred namecobG
eggNOG descriptionPrecorrin-3B synthase
Orthologous groupCOG0155
EC number EC 1.14.13.83
KEGG orthology K02229
KEGG pathways map00860, map01100

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 0.501 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 4 synonymous, 5 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
NIR_SIR_ferrPF03460.23 8.3e-1321–76 Nitrite/Sulfite reductase ferredoxin-like half domain

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

Closest characterised functional partner: cobIJ (bifunctional S-adenosyl-L-methionine-precorrin-2 methyl transferase/precorrin-3 methylase), high confidence from genomic context alone (score 997 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2066 cobIJ bifunctional S-adenosyl-L-methionine-precorrin-2 methyl transferase/precorrin-3 methylase 998 997 ctx neighborhood:876 cooccurence:760 database:900 textmining:529
Rv2065 cobH precorrin-8X methylmutase 998 992 ctx neighborhood:876 fusion:806 cooccurence:665 textmining:818
Rv1286 cysC adenylyl-sulfate kinase 992 987 coexpression:985 textmining:418
Rv2063A mazF7 mRNA interferase MazF7 897 897 ctx neighborhood:882
Rv2062c cobN cobalamin biosynthesis protein CobN 952 853 ctx neighborhood:639 cooccurence:604 textmining:690
Rv2847c cysG multifunctional uroporphyrin-III C-methyltransferase/precorrin-2 oxidase/ferrochelatase 882 825 coexpression:799
Rv2063 mazE7 antitoxin MazE7 786 786 ctx neighborhood:781
Rv2072c cobL precorrin-6Y C(5,15)-methyltransferase 939 774 ctx cooccurence:737 textmining:745
Rv2070c cobK precorrin-6A reductase 910 759 ctx cooccurence:744 textmining:644
Rv2392 cysH phosphoadenosine phosphosulfate reductase 744 720 coexpression:663
Rv2398c cysW sulfate ABC transporter permease CysW 744 711 coexpression:694
Rv0511 hemD uroporphyrin-III C-methyltransferase 893 690 coexpression:647 textmining:670
Rv1859 modC molybdenum ABC transporter ATP-binding protein ModC 709 682 coexpression:671
Rv2397c cysA1 sulfate ABC transporter ATP-binding protein CysA 708 680 coexpression:669
Rv1285 cysD sulfate adenylyltransferase subunit 2 698 670 coexpression:659

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: precorrin-3B synthase
  • MTBC0 PGAP product: precorrin-3B synthase
  • Pfam (hmmscan --cut_ga): NIR_SIR_ferr PF03460.23 (E=8e-13)
  • (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_216580.1)
  • Domains: Pfam-A via hmmscan --cut_ga — NIR_SIR_ferr (PF03460.23)
  • 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 COG0155
  • Curated reference: UniProt Q10675 (TrEMBL, unreviewed; 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 — 45 functional partner(s); context anchor cobIJ
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_002198|Rv2064|cobG
MAGTRDADACPGALRPHQAADGALARIRLPGGMITAAQLATLASVASDFGSATLELTARGNVQLRGIRDVAAVADAVAKAGLLPSATHERVRNIVASPLSGRAGGLADVRAWVGELDAAIRAEPRLAELGGRFWFGLDDGRADVSGLGADVGVQVFPDGPRLLLTGRDTGVRVADVAETLIEVALRFVKIRETAWRVTELADIGELQSGVELGPSVRPVTKTPVGWIPQDDSRVTLGAAVPLGVLPARVAECLAAIEAPLVITPWRSVLICDLDDATADAALRVLAPLGLVFDENSPWLNISACTGSPGCAHSAADVRADAARSLNVESAGHRHFVGCERACGSPPAGEVLVATGGGYRRLRP