Rv3377c Resolved · high auto-curated

H37Rv Rv3377c · MTBC0 mtbc0_003592 · 501 aa · 3817565–3819070 (-) · RefSeq NP_217894.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)type B diterpene cyclase
MTBC0 PGAP re-annotationtype B diterpene cyclase
Revised (this work)Type B diterpene cyclase. Pfam: SQHop_cyclase_C (PF13243.13).

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

Curated reference (UniProt)

UniProt O50406 SwissProt · reviewed · Evidence at protein level
UniProt nameType B diterpene cyclase
EC (curated) EC 5.5.1.16
Curated functionCatalyzes the formation of tuberculosinyl diphosphate from geranylgeranyl diphosphate (GGPP). It could also react with (14R/S)-14,15-oxidoGGPP to generate 3alpha- and 3beta-hydroxytuberculosinyl diphosphate.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category I Lipid transport and metabolism
eggNOG descriptionSqualene--hopene cyclase
Orthologous groupCOG1657
EC number EC 5.5.1.16
KEGG orthology K17811
Gene Ontology (61) GO:0000287, GO:0003674, GO:0003824, GO:0005488, GO:0006629, GO:0006644, GO:0006720, GO:0006721, GO:0006793, GO:0006796, GO:0006950, GO:0007154 +49 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) pseudogene candidate

pN/pS 1.165 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 4 synonymous, 15 missense, 0 nonsense, 2 frameshift
Disruption 2 distinct premature-stop/frameshift site(s); most common in 10.08% of strains (14632) · 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
SQHop_cyclase_CPF13243.13 9.5e-08338–421 Squalene-hopene cyclase C-terminal domain

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

Closest characterised functional partner: Rv3378c (diterpene synthase), high confidence from genomic context alone (score 938 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3378c diterpene synthase 991 938 ctx neighborhood:882 database:500 textmining:872
Rv1814 erg3 membrane-bound C-5 sterol desaturase 879 842 experimental:785
Rv3379c dxs2 1-deoxy-D-xylulose-5-phosphate synthase 937 801 ctx neighborhood:801 textmining:697
Rv2293c hyp hypothetical protein 737 723 ctx cooccurence:712
Rv3383c idsB polyprenyl synthetase IdsB 925 567 textmining:836
Rv1004c membrane protein 561 561 ctx cooccurence:561
Rv3347c PPE55 PPE family protein PPE55 551 551 ctx cooccurence:551
Rv3468c dTDP-glucose 4,6-dehydratase 572 548
Rv0355c PPE8 PPE family protein PPE8 548 548 ctx cooccurence:548
Rv0304c PPE5 PPE family protein PPE5 542 542 ctx cooccurence:542
Rv1753c PPE24 PPE family protein PPE24 539 539 ctx cooccurence:539
Rv3350c PPE56 PPE family protein PPE56 538 538 ctx cooccurence:538
Rv1745c idi isopentenyl-diphosphate delta-isomerase 604 532 coexpression:440
Rv1917c PPE34 PPE family protein PPE34 532 532 ctx cooccurence:532
Rv1651c PE_PGRS30 PE-PGRS family protein PE_PGRS30 530 531 ctx cooccurence:530

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: type B diterpene cyclase
  • MTBC0 PGAP product: type B diterpene cyclase
  • Pfam (hmmscan --cut_ga): SQHop_cyclase_C PF13243.13 (E=1e-07)
  • (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_217894.1)
  • Domains: Pfam-A via hmmscan --cut_ga — SQHop_cyclase_C (PF13243.13)
  • 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 COG1657
  • Curated reference: UniProt O50406 (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 — 77 functional partner(s); context anchor Rv3378c
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_003592|Rv3377c|
METFRTLLAKAALGNGISSTAYDTAWVAKLGQLDDELSDLALNWLCERQLPDGSWGAEFPFCYEDRLLSTLAAMISLTSNKHRRRRAAQVEKGLLALKNLTSGAFEGPQLDIKDATVGFELIAPTLMAEAARLGLAICHEESILGELVGVREQKLRKLGGSKINKHITAAFSVELAGQDGVGMLDVDNLQETNGSVKYSPSASAYFALHVKPGDKRALAYISSIIQAGDGGAPAFYQAEIFEIVWSLWNLSRTDIDLSDPEIVRTYLPYLDHVEQHWVRGRGVGWTGNSTLEDCDTTSVAYDVLSKFGRSPDIGAVLQFEDADWFRTYFHEVGPSISTNVHVLGALKQAGYDKCHPRVRKVLEFIRSSKEPGRFCWRDKWHRSAYYTTAHLICAASNYDDALCSDAIGWILNTQRPDGSWGFFDGQATAEETAYCIQALAHWQRHSGTSLSAQISRAGGWLSQHCEPPYAPLWIAKTLYCSATVVKAAILSALRLVDESNQ