PPE3 Family assigned · medium auto-curated

H37Rv Rv0280 · MTBC0 - · 536 aa · 339364–340974 (+) · RefSeq YP_177709.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)PPE family protein PPE3
MTBC0 PGAP re-annotation
Revised (this work)PPE family protein PPE3. Pfam: PPE (PF00823.26), PPE-PPW (PF18878.6).

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

Annotated on the H37Rv protein: this gene has no 1:1 ancestral MTBC0 anchor (PE/PPE, paralogue, IS element, or otherwise unanchored CDS).

Curated reference (UniProt)

UniProt P9WI45 SwissProt · reviewed · Evidence at protein level
UniProt nameUncharacterized PPE family protein PPE3

UniProt still lists this protein as Uncharacterized PPE family protein PPE3; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category N Cell motility
eggNOG descriptionPPE family
Orthologous groupCOG5651

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 1.4 · diversifying/relaxed
Polymorphic sites (≥ 0.1% of strains) 3 synonymous, 12 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
PPEPF00823.26 1.1e-604–166 PPE family
PPE-PPWPF18878.6 4.0e-20473–520 PPE-PPW subfamily C-terminal region

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

Closest characterised functional partner: eccA3 (ESX-3 secretion system protein EccA), high confidence from genomic context alone (score 845 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2990c hyp hypothetical protein 971 860 coexpression:860 textmining:803
Rv0282 eccA3 ESX-3 secretion system protein EccA 876 845 ctx neighborhood:416 coexpression:746
Rv0106 hyp hypothetical protein 888 804 coexpression:804 textmining:457
Rv2058c rpmB2 50S ribosomal protein L28 897 798 coexpression:798 textmining:514
Rv0281 S-adenosylmethionine-dependent methyltransferase 826 773 ctx neighborhood:713
Rv2059 hyp hypothetical protein 778 732 coexpression:732
Rv0283 eccB3 ESX-3 secretion system protein EccB3 688 584 ctx neighborhood:416
Rv0284 eccC3 ESX-3 secretion system protein EccC3 636 535 ctx neighborhood:416
Rv0286 PPE4 PPE family protein PPE4 469 437 ctx neighborhood:401
Rv0285 PE5 PE family protein PE5 450 416 ctx neighborhood:416
Rv0279c PE_PGRS4 PE-PGRS family protein PE_PGRS4 413 413 ctx neighborhood:413
Rv0287 esxG ESAT-6 like protein EsxG 580 354
Rv0289 espG3 ESX-3 secretion-associated protein EspG3 464 333
Rv0288 esxH ESAT-6-like protein EsxH 512 320
Rv0291 mycP3 membrane-anchored mycosin MycP 672 299 textmining:551

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

  • Annotation from H37Rv (no MTBC0 1:1 anchor; H37Rv protein used): PPE family protein PPE3
  • Pfam (hmmscan --cut_ga): PPE PF00823.26 (E=1e-60), PPE-PPW PF18878.6 (E=4e-20)
  • (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 YP_177709.1)
  • Domains: Pfam-A via hmmscan --cut_ga — PPE (PF00823.26), PPE-PPW (PF18878.6)
  • 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 COG5651
  • Curated reference: UniProt P9WI45 (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 — 23 functional partner(s); context anchor eccA3
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv0280|PPE3
MTLWMASPPEVHSALLSSGPGPGSVLSAAGVWSSLSAEYAAVADELIGLLGAVQTGAWQGPSAAAYVAAHAPYLAWLMRASETSAEAAARHETVAAAYTTAVAAMPTLVELAANHTLHGVLVATNFFGINTIPIALNEADYARMWTQAASTMATYQAVAEAAVASAPQTTPAPPILAAEAADDDHDHDHDHGGEPTPLDYLVAEILRIISGGRLIWDPAEGTMNGIPFEDYTDAAQPIWWVVRAIEFSKDFETFVQELFVNPVEAFQFYFELLLFDYPTHIVQIVEALSQSPQLLAVALGSVISNLGAVTGFAGLSGLAGMQPAAIPALAPVAAAPSTLPAVAMAPTMAAPGAAVASAAAPASAPAASTVASATPAPPPAPGAAGFGYPYAIAPPGIGFGSGMSASASAQRKAPQPDSAAAAAAAAAVRDQARARRRRRVTRRGYGDEFMDMNIDVDPDWGPPPGEDPVTSTVASDRGAGHLGFAGTARREAVADAAGMTTLAGDDFGDGPTTPMVPGSWDPDRDAPGSAEPGDRG