PPE51 Family assigned · medium auto-curated

H37Rv Rv3136 · MTBC0 - · 380 aa · 3501794–3502936 (+) · RefSeq YP_177935.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)PPE family protein PPE51
MTBC0 PGAP re-annotation
Revised (this work)PPE family protein PPE51. Pfam: PPE (PF00823.26), PPE-SVP (PF12484.14).

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 P9WHY3 SwissProt · reviewed · Evidence at protein level
UniProt nameTransporter PPE51
Curated functionSmall molecule-selective channel required for the uptake of nutrients across the outer mycomembrane. Transports glycerol and glucose. Involved in sensitivity to M.tuberculosis growth inhibitory agrichemical 3,3-bis-di(methylsulfonyl)propionamide (3bMP1). Transports maltose and lactose disaccharides. Involved in sensitivity to bactericidal thio-disaccharide T-6 compound (1,6-anhydro-3-deoxy-4-S-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-D-glycero-hexopyranos-2-ulose). Transports extracellular trehalose, a component of the cell envelope, and trehalose analog, 6-azido trehalose (6-TreAz), whi.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category N Cell motility
eggNOG descriptionPolymorphic PE/PPE proteins C terminal
Orthologous groupCOG5651
Gene Ontology (6) GO:0005575, GO:0005618, GO:0005623, GO:0030312, GO:0044464, GO:0071944

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 0.954 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 2 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
PPEPF00823.26 9.0e-642–164 PPE family
PPE-SVPPF12484.14 8.1e-19300–376 PPE-SVP subfamily C-terminal region

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

Closest characterised functional partner: PPE50 (PPE family protein PPE50), high confidence from genomic context alone (score 940 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3135 PPE50 PPE family protein PPE50 941 940 ctx neighborhood:591 coexpression:860
Rv3137 hisN histidinol-phosphatase 510 339
Rv1747 ABC transporter ATP-binding protein/permease 438 51 textmining:433
Rv2214c ephD oxidoreductase EphD 440 50 textmining:435
Rv1901 cinA competence damage-inducible protein CinA 436 47 textmining:433
Rv1068c PE_PGRS20 PE-PGRS family protein PE_PGRS20 698 41 textmining:698

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 PPE51
  • Pfam (hmmscan --cut_ga): PPE PF00823.26 (E=9e-64), PPE-SVP PF12484.14 (E=8e-19)
  • (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_177935.1)
  • Domains: Pfam-A via hmmscan --cut_ga — PPE (PF00823.26), PPE-SVP (PF12484.14)
  • 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 P9WHY3 (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 — 6 functional partner(s); context anchor PPE50
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv3136|PPE51
MDFALLPPEVNSARMYTGPGAGSLLAAAGGWDSLAAELATTAEAYGSVLSGLAALHWRGPAAESMAVTAAPYIGWLYTTAEKTQQTAIQARAAALAFEQAYAMTLPPPVVAANRIQLLALIATNFFGQNTAAIAATEAQYAEMWAQDAAAMYGYATASAAAALLTPFSPPRQTTNPAGLTAQAAAVSQATDPLSLLIETVTQALQALTIPSFIPEDFTFLDAIFAGYATVGVTQDVESFVAGTIGAESNLGLLNVGDENPAEVTPGDFGIGELVSATSPGGGVSASGAGGAASVGNTVLASVGRANSIGQLSVPPSWAAPSTRPVSALSPAGLTTLPGTDVAEHGMPGVPGVPVAAGRASGVLPRYGVRLTVMAHPPAAG