chp2 Resolved · high auto-curated

H37Rv Rv1184c · MTBC0 mtbc0_001272 · 359 aa · 1332974–1334053 (-) · RefSeq NP_215700.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotationdiacyltrehalose acyltransferase Chp2
Revised (this work)Diacyltrehalose acyltransferase Chp2. Pfam: PE-PPE (PF08237.18).

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

Curated reference (UniProt)

UniProt O50440 SwissProt · reviewed · Evidence at protein level
UniProt nameDiacyltrehalose acyltransferase Chp2
EC (curated) EC 2.3.1.-
Curated functionInvolved in the final steps of polyacyltrehalose (PAT) biosynthesis. Catalyzes the transfer of three mycolipenoyl groups onto diacyltrehalose (DAT) to form PAT.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category N Cell motility
eggNOG descriptiondomain protein
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 0.27 · purifying
Polymorphic sites (≥ 0.1% of strains) 5 synonymous, 4 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
PE-PPEPF08237.18 7.5e-8179–316 PE-PPE domain

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

Closest characterised functional partner: fadD21 (fatty-acid--CoA ligase FadD21), medium confidence from genomic context alone (score 595 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv1183 mmpL10 transmembrane transport protein MmpL10 850 747 coexpression:733 textmining:434
Rv3822 chp1 hyp hypothetical protein 783 740 coexpression:740
Rv1185c fadD21 fatty-acid--CoA ligase FadD21 843 595 ctx neighborhood:483 textmining:630
Rv1182 papA3 acyltransferase papA3 726 532 database:500 textmining:440
Rv3487c lipF carboxylesterase LipF 467 359
Rv3824c papA1 acyltransferase 507 317
Rv3823c mmpL8 integral membrane transport protein MmpL8 414 293
Rv3825c pks2 phthioceranic/hydroxyphthioceranic acid synthase 532 210 textmining:433
Rv1181 pks4 polyketide beta-ketoacyl synthase 545 95 textmining:518
Rv1180 pks3 polyketide beta-ketoacyl synthase 542 93 textmining:516
Rv1157c hyp hypothetical protein 487 56 textmining:479
Rv3207c hyp hypothetical protein 443 55 textmining:435
Rv3084 lipR acetyl-hydrolase LipR 542 53 textmining:537
Rv2190c ripC endopeptidase 514 47 textmining:511
Rv0315 beta-1,3-glucanase 422 44 textmining:421

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: hypothetical protein
  • MTBC0 PGAP product: diacyltrehalose acyltransferase Chp2
  • Pfam (hmmscan --cut_ga): PE-PPE PF08237.18 (E=8e-81)
  • (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_215700.1)
  • Domains: Pfam-A via hmmscan --cut_ga — PE-PPE (PF08237.18)
  • 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 COG5651
  • Curated reference: UniProt O50440 (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 — 18 functional partner(s); context anchor fadD21
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_001272|Rv1184c|chp2
MKRVIAGAFAVWLVGWAGGFGTAIAASEPAYPWAPGPPPSPSPVGDASTAKVVYALGGARMPGIPWYEYTNQAGSQYFPNAKHDLIDYPAGAAFSWWPTMLLPPGSHQDNMTVGVAVKDGTNSLDNAIHHGTDPAAAVGLSQGSLVLDQEQARLANDPTAPAPDKLQFTTFGDPTGRHAFGASFLARIFPPGSHIPIPFIEYTMPQQVDSQYDTNHVVTAYDGFSDFPDRPDNLLAVANAAIGAAIAHTPIGFTGPGDVPPQNIRTTVNSRGATTTTYLVPVNHLPLTLPLRYLGMSDAEVDQIDSVLQPQIDAAYARNDNWFTRPVSVDPVRGLDPLTAPGSIVEGARGLLGSPAFGG