gca Resolved · high auto-curated

H37Rv Rv0112 · MTBC0 mtbc0_000122 · 318 aa · 136454–137410 (+) · RefSeq NP_214626.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)GDP-mannose 4,6-dehydratase
MTBC0 PGAP re-annotationGDP-mannose 4%2C6-dehydratase
Revised (this work)GDP-mannose 4%2C6-dehydratase. Pfam: RmlD_sub_bind (PF04321.24), Epimerase (PF01370.28), GDP_Man_Dehyd (PF16363.12).

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

Curated reference (UniProt)

UniProt O53634 TrEMBL · unreviewed · Evidence at protein level
UniProt namePossible GDP-mannose 4,6-dehydratase Gca

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category G Carbohydrate transport and metabolism
M Cell wall / membrane / envelope biogenesis
Preferred namegca
eggNOG descriptionGDP-mannose 4,6 dehydratase
Orthologous groupCOG0451
EC number EC 1.1.1.281
KEGG orthology K15856
KEGG pathways map00051, map00520

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 0.721 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 3 synonymous, 6 missense, 1 nonsense, 1 frameshift
Disruption 2 distinct premature-stop/frameshift site(s); most common in 0.15% of strains (222) · clonal

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
RmlD_sub_bindPF04321.24 2.4e-101–157 RmlD substrate binding domain
EpimerasePF01370.28 9.0e-494–238 NAD dependent epimerase/dehydratase family
GDP_Man_DehydPF16363.12 5.3e-595–304 GDP-mannose 4,6 dehydratase

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

Closest characterised functional partner: gmhA (phosphoheptose isomerase), high confidence from genomic context alone (score 952 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1511 gmdA GDP-D-mannose dehydratase GmdA 956 955 database:900
Rv0113 gmhA phosphoheptose isomerase 954 952 ctx neighborhood:579 coexpression:863
Rv0114 gmhB D-glycero-alpha-D-manno-heptose-1,7-bisphosphate 7-phosphatase 937 934 ctx neighborhood:509 coexpression:829
Rv0115 hddA D-alpha-D-heptose-7-phosphate kinase HddA 934 931 ctx neighborhood:509 coexpression:827
Rv1512 epiA nucleotide-sugar epimerase EpiA 911 912 database:900
Rv0705 rpsS 30S ribosomal protein S19 817 818 experimental:463 database:574
Rv0700 rpsJ 30S ribosomal protein S10 815 812 experimental:463 database:557
Rv0682 rpsL 30S ribosomal protein S12 860 807 experimental:463 database:573
Rv3459c rpsK 30S ribosomal protein S11 805 798 experimental:463 database:558
Rv0710 rpsQ 30S ribosomal protein S17 804 798 experimental:463 database:578
Rv0707 rpsC 30S ribosomal protein S3 804 797 experimental:463 database:578
Rv0721 rpsE 30S ribosomal protein S5 797 790 experimental:463 database:575
Rv2056c rpsN2 30S ribosomal protein S14 789 790 experimental:436 database:548
Rv0717 rpsN1 30S ribosomal protein S14 788 789 experimental:436 database:548
Rv0718 rpsH 30S ribosomal protein S8 795 788 experimental:463 database:578

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: GDP-mannose 4,6-dehydratase
  • MTBC0 PGAP product: GDP-mannose 4%2C6-dehydratase
  • Pfam (hmmscan --cut_ga): RmlD_sub_bind PF04321.24 (E=2e-10), Epimerase PF01370.28 (E=9e-49), GDP_Man_Dehyd PF16363.12 (E=5e-59)
  • (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_214626.1)
  • Domains: Pfam-A via hmmscan --cut_ga — RmlD_sub_bind (PF04321.24), Epimerase (PF01370.28), GDP_Man_Dehyd (PF16363.12)
  • 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 COG0451
  • Curated reference: UniProt O53634 (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 — 90 functional partner(s); context anchor gmhA
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_000122|Rv0112|gca
MKVWITGAGGMMGSHLAEMLLAAGHDVYATYCRPTIDPSDLQFNGAEVDITDWCSVYDSIATFRPDAVFHLAAQSYPAVSWARPVETLTTNMVGTAIVFEALRRVRPHAKIIVAGSSAEYGFVDPSEVPINERRELRPLHPYGVSKAATDMLAYQYHKSYGMHTVVARIFNCTGPRKVGDALSDFVRRCTWLEHHPEQSAIRVGNLKTKRTIVDVRDLNRALMLMLDKGEAGADYNVGGSIAYEMGDVLKQVIAACKRDDIVPEVDPALLRPTDEKIIYGDCSKLAAITGWQQEICLTQTIADMFDYWRSKSESALMV