PPE44 Family assigned · medium auto-curated

H37Rv Rv2770c · MTBC0 - · 382 aa · 3079309–3080457 (-) · RefSeq YP_177677.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)PPE family protein PPE44
MTBC0 PGAP re-annotation
Revised (this work)PPE family protein PPE44. 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 P9WHZ3 SwissProt · reviewed · Evidence at protein level
UniProt namePPE family protein PPE44
Curated functionVirulence factor that modulates host innate immune response. Induces the production of the pro-inflammatory cytokines IL-6 and IL-12p40 in macrophages via NF-kappa-B, ERK1/2 and p38 signaling axis. Can enhance M.smegmatis survival within macrophages and under stresses such as H(2)O(2), SDS, diamide exposure and low pH condition. Promotes the death of macrophage by apoptosis in the later stage of infection.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category N Cell motility
eggNOG descriptionPolymorphic PE/PPE proteins C terminal
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 0.372 · purifying
Polymorphic sites (≥ 0.1% of strains) 10 synonymous, 10 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 6.5e-592–164 PPE family
PPE-SVPPF12484.14 3.1e-17300–378 PPE-SVP subfamily C-terminal region

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

Closest characterised functional partner: PE27 (PE family protein PE27), medium confidence from genomic context alone (score 447 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1040c PE8 PE family protein PE8 904 899 experimental:891
Rv1794 espG5 hyp hypothetical protein 891 891 experimental:891
Rv2771c hyp hypothetical protein 513 512 ctx neighborhood:506
Rv2769c PE27 PE family protein PE27 489 447 ctx neighborhood:447
Rv2336 hyp hypothetical protein 870 47 textmining:870
Rv1345 mbtM long-chain-fatty-acid--ACP ligase MbtM 659 44 textmining:658
Rv0288 esxH ESAT-6-like protein EsxH 628 44 textmining:627
Rv2819c csm5 CRISPR type III-associated RAMP protein Csm5 805 43 textmining:805
Rv1320c adenylate cyclase 753 41 textmining:753
Rv1806 PE20 PE family protein PE20 528 41 textmining:529

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 PPE44
  • Pfam (hmmscan --cut_ga): PPE PF00823.26 (E=7e-59), PPE-SVP PF12484.14 (E=3e-17)
  • (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_177677.1)
  • 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 P9WHZ3 (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 — 10 functional partner(s); context anchor PE27
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv2770c|PPE44
MDFGALPPEVNSARMYGGAGAADLLAAAAAWNGIAVEVSTAASSVGSVITRLSTEHWMGPASLSMAAAVQPYLVWLTCTAESSALAAAQAMASAAAFETAFALTVPPAEVVANRALLAELTATNILGQNVSAIAATEARYGEMWAQDASAMYGYAAASAVAARLNPLTRPSHITNPAGLAHQAAAVGQAGASAFARQVGLSHLISDVADAVLSFASPVMSAADTGLEAVRQFLNLDVPLFVESAFHGLGGVADFATAAIGNMTLLADAMGTVGGAAPGGGAAAAVAHAVAPAGVGGTALTADLGNASVVGRLSVPASWSTAAPATAAGAALDGTGWAVPEEDGPIAVMPPAPGMVVAANSVGADSGPRYGVKPIVMPKHGLF