ltp2 Resolved · high auto-curated

H37Rv Rv3540c · MTBC0 mtbc0_003757 · 386 aa · 4003176–4004336 (-) · RefSeq NP_218057.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)lipid transfer protein
MTBC0 PGAP re-annotationlipid-transfer protein
Revised (this work)Lipid-transfer protein. Pfam: Thiolase_N (PF00108.30), Thiolase_C_1 (PF22691.3).

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

Curated reference (UniProt)

UniProt I6Y3T7 SwissProt · reviewed · Evidence at protein level
UniProt name17-hydroxy-3-oxo-4-pregnene-20-carboxyl-CoA lyase
EC (curated) EC 4.1.3.-
Curated functionInvolved in cholesterol side chain degradation. When associated with the ChsH1/ChsH2 hydratase, catalyzes the retroaldol cleavage of 17-hydroxy-3-oxo-4-pregnene-20-carboxyl-CoA (17-HOPC-CoA) produced by the hydratase, forming androst-4-ene-3,17-dione and propionyl-CoA.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category I Lipid transport and metabolism
Preferred nameltp2
eggNOG descriptionlipid-transfer protein
Orthologous groupCOG0183

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 0.208 · purifying
Polymorphic sites (≥ 0.1% of strains) 5 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
Thiolase_NPF00108.30 1.1e-068–227 Thiolase, N-terminal domain
Thiolase_C_1PF22691.3 8.6e-29271–378 Thiolase C-terminal domain-like

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

Closest characterised functional partner: fadE29 (acyl-CoA dehydrogenase FadE29), high confidence from genomic context alone (score 980 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3542c chsH2 hyp hypothetical protein 999 999 ctx neighborhood:882 cooccurence:761 coexpression:866 experimental:508 database:500
Rv3541c chsH1 hyp hypothetical protein 999 998 ctx neighborhood:882 cooccurence:730 coexpression:857 database:500 textmining:809
Rv3543c fadE29 acyl-CoA dehydrogenase FadE29 998 980 ctx neighborhood:881 cooccurence:602 coexpression:577 textmining:907
Rv0860 fadB fatty oxidation protein FadB 969 966 coexpression:697 experimental:804 database:447
Rv3544c fadE28 acyl-CoA dehydrogenase FadE28 995 962 ctx neighborhood:881 cooccurence:476 textmining:878
Rv3521 hyp hypothetical protein 916 895 ctx cooccurence:706 coexpression:424 experimental:415
Rv3550 echA20 enoyl-CoA hydratase EchA20 907 877 ctx cooccurence:526 database:447
Rv3545c cyp125 steroid C26-monooxygenase 980 865 ctx neighborhood:836 textmining:865
Rv3562 fadE31 acyl-CoA dehydrogenase FadE31 843 834 ctx cooccurence:716
Rv3560c fadE30 acyl-CoA dehydrogenase FadE30 915 826 ctx cooccurence:701 textmining:535
Rv3537 kstD 3-oxosteroid 1-dehydrogenase 848 815 ctx cooccurence:546 database:500
Rv3551 CoA-transferase subunit alpha 846 805 ctx cooccurence:753
Rv3552 CoA-transferase subunit beta 813 805 ctx cooccurence:750
Rv3516 echA19 enoyl-CoA hydratase EchA19 859 785 database:447
Rv3573c fadE34 acyl-CoA dehydrogenase FadE34 924 783 ctx cooccurence:628 textmining:668

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: lipid transfer protein
  • MTBC0 PGAP product: lipid-transfer protein
  • Pfam (hmmscan --cut_ga): Thiolase_N PF00108.30 (E=1e-06), Thiolase_C_1 PF22691.3 (E=9e-29)
  • (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_218057.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Thiolase_N (PF00108.30), Thiolase_C_1 (PF22691.3)
  • 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 COG0183
  • Curated reference: UniProt I6Y3T7 (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 — 124 functional partner(s); context anchor fadE29
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_003757|Rv3540c|ltp2
MLSGQAAIVGIGATDFSKNSGRSELRLAAEAVLDALADAGLSPTDVDGLTTFTMDTNTEIAVARAAGIGELTFFSKIHYGGGAACATVQHAAMAVATGVADVVVAYRAFNERSGMRFGQVQTRLTENADSTGVDNSFSYPHGLSTPAAQVAMIARRYMHLSGATSRDFGAVSVADRKHAANNPKAYFYGKPITIEDHQNSRWIAEPLRLLDCCQETDGAVAIVVTSAARARDLKQRPVVIEAAAQGCSPDQYTMVSYYRPELDGLPEMGLVGRQLWAQSGLTPADVQTAVLYDHFTPFTLIQLEELGFCGKGEAKDFIADGAIEVGGRLPINTHGGQLGEAYIHGMNGIAEGVRQLRGTSVNPVAGVEHVLVTAGTGVPTSGLILG