35kd_ag Family assigned · medium auto-curated

H37Rv Rv2744c · MTBC0 - · 270 aa · 3057251–3058063 (-) · RefSeq YP_177903.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotation
Revised (this work)Contains PspA_IM30 (PF04012.18) domain(s); putative function inferred from the domain architecture.

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 P9WHP5 SwissProt · reviewed · Evidence at protein level
UniProt namePspA protein
Curated functionInvolved in resistance to stress. Facilitates intracellular growth of M.tuberculosis. Associates with and regulates lipid droplets (LDs) homeostasis under conditions of stress and may regulate non-replicating persistence (NRP). Could be involved in preservation of envelope integrity and tolerance to surface stress. Has an inhibitory effect on ClgR activity. May block ClgR activity after stress and then, form a multiprotein complex with Rv2743c-Rv2742c, leading to the release of ClgR.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category K Transcription
T Signal transduction mechanisms
Preferred namepspA
eggNOG descriptionphage shock protein a (IM30), suppresses
Orthologous groupCOG1842
KEGG orthology K03969
Gene Ontology (11) GO:0005575, GO:0005618, GO:0005622, GO:0005623, GO:0005737, GO:0005886, GO:0016020, GO:0030312, GO:0044424, 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) pseudogene candidate

pN/pS 2.15 · diversifying/relaxed
Polymorphic sites (≥ 0.1% of strains) 1 synonymous, 6 missense, 1 nonsense, 0 frameshift
Disruption 1 distinct premature-stop/frameshift site(s); most common in 1.41% of strains (2042) · 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
PspA_IM30PF04012.18 2.5e-553–241 PspA/IM30 family

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

Closest characterised functional partner: clgR (transcriptional regulator ClgR), high confidence from genomic context alone (score 925 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv2745c clgR transcriptional regulator ClgR 973 925 ctx neighborhood:759 coexpression:703 textmining:665
Rv2743c hyp hypothetical protein 971 860 ctx neighborhood:799 textmining:804
Rv0563 htpX protease HtpX 821 822 coexpression:816
Rv2710 sigB RNA polymerase sigma factor SigB 834 808 coexpression:801
Rv2468c hyp hypothetical protein 810 807 ctx cooccurence:738
Rv2179c 3'-5' exoribonuclease 773 774 ctx cooccurence:773
Rv0948c chorismate mutase 770 770 ctx cooccurence:768
Rv3605c hyp hypothetical protein 767 767 ctx cooccurence:767
Rv3311 hyp hypothetical protein 743 743 ctx cooccurence:742
Rv2694c hyp hypothetical protein 747 737 coexpression:732
Rv2711 ideR iron-dependent repressor and activator IdeR 740 731 coexpression:731
Rv1209 hyp hypothetical protein 729 725 ctx cooccurence:719
Rv3412 hyp hypothetical protein 714 714 ctx cooccurence:710
Rv0049 hyp hypothetical protein 704 705 ctx cooccurence:703
Rv0813c hyp hypothetical protein 695 695 ctx cooccurence:692

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): hypothetical protein
  • Pfam (hmmscan --cut_ga): PspA_IM30 PF04012.18 (E=3e-55)
  • (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_177903.1)
  • Domains: Pfam-A via hmmscan --cut_ga — PspA_IM30 (PF04012.18)
  • 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 COG1842
  • Curated reference: UniProt P9WHP5 (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 — 76 functional partner(s); context anchor clgR
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv2744c|35kd_ag
MANPFVKAWKYLMALFSSKIDEHADPKVQIQQAIEEAQRTHQALTQQAAQVIGNQRQLEMRLNRQLADIEKLQVNVRQALTLADQATAAGDAAKATEYNNAAEAFAAQLVTAEQSVEDLKTLHDQALSAAAQAKKAVERNAMVLQQKIAERTKLLSQLEQAKMQEQVSASLRSMSELAAPGNTPSLDEVRDKIERRYANAIGSAELAESSVQGRMLEVEQAGIQMAGHSRLEQIRASMRGEALPAGGTTATPRPATETSGGAIAEQPYGQ