Rv0999 Family assigned · low

H37Rv Rv0999 · MTBC0 - · 252 aa · 1115767–1116525 (+) · RefSeq NP_215514.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotation
Revised (this work)Lipoprotein / outer-membrane-associated protein (lipoprotein-like beta fold); structurally solved but functionally uncharacterised fold RefSeq leaves this locus uncharacterised.

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 O05582 TrEMBL · unreviewed · Evidence at protein level
UniProt nameDUF5642 domain-containing protein

Functional vocabulary (eggNOG-mapper, orthology transfer)

Orthologous group2AQ7W

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 0.25 · purifying
Polymorphic sites (≥ 0.1% of strains) 3 synonymous, 2 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
DUF5642PF18702.8 4.7e-7463–251 Domain of unknown function (DUF5642)

Structural neighbours (Foldseek on the ESMFold model, exploratory)

ESMFold model confidence: mean pLDDT 82.2 (confident). A confident model makes the fold comparison meaningful.

Best matches against the PDB, ranked by Foldseek homology probability. A high probability / TM-score suggests a shared fold; unless flagged sig (E < 0.01) these are fold hypotheses, not assignments.

TargetProbTME-valueDescription
4tmd-assembly1_A 1.00 0.95 1.6e-24 sig 4tmd-assembly1_A X-ray structure of Putative uncharacterized protein (Rv0999 ortholog) from Mycobacterium smegmatis
4qdc-assembly1_A 0.33 0.34 6.9e-02 4qdc-assembly1_A Crystal structure of 3-ketosteroid-9-alpha-hydroxylase 5 (KshA5) from R. rhodochrous in complex with FE2/S2 (INORGANIC) CLUSTER
8c5w-assembly1_A 0.25 0.38 2.5e-01 8c5w-assembly1_A Crystal Structure of Penicillin-binding Protein 3 (PBP3) from Staphylococcus Epidermidis in complex with Cefotaxime
6mna-assembly1_A 0.21 0.30 1.1e-01 6mna-assembly1_A Crystal structure of LpqN involved in cell envelope biogenesis of Mycobacterium tuberculosis
4qdd-assembly1_A 0.16 0.25 8.7e-02 4qdd-assembly1_A Crystal structure of 3-ketosteroid-9-alpha-hydroxylase 5 (KshA5) from R. rhodochrous in complex with 1,4-30Q-CoA
6w3f-assembly2_B 0.14 0.53 1.9e+00 6w3f-assembly2_B Rd1NTF2_05_I64F_A80G_T94P_D101K_L106W
4ye5-assembly2_B 0.14 0.42 1.1e+00 4ye5-assembly2_B The crystal structure of a peptidoglycan synthetase from Bifidobacterium adolescentis ATCC 15703
4wmc-assembly4_H 0.13 0.32 2.9e-01 4wmc-assembly4_H OXA-48 covalent complex with Avibactam inhibitor

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

Closest characterised functional partner: Rv0998 (acetyltransferase Pat), high confidence from genomic context alone (score 733 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv0998 acetyltransferase Pat 733 733 ctx neighborhood:732
Rv0997 hyp hypothetical protein 654 654 ctx neighborhood:653
Rv2903c lepB signal peptidase 544 47 textmining:542
Rv0519c membrane protein 870 46 textmining:870
Rv2253 hyp hypothetical protein 803 41 textmining:803

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

  • HHpred: top hit 4TMD uncharacterised SSGCID structure 99.94% E2.8e-24 (193 cols); then ~20 convergent hits all bacterial lipoproteins/OMP/secretion components 60-94% (LptM, YifL, M.tb LpqN/LpqE, BamC/E, TssJ, CagT/VirB7)
  • HHpred web (MPI Bioinformatics Toolkit, profile-profile remote homology), interpreted in project 'Still unknown gene function', 2026-06-10. A fold/family-level assignment, not a demonstrated function.

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_215514.1)
  • Domains: Pfam-A via hmmscan --cut_ga — DUF5642 (PF18702.8)
  • 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 2AQ7W
  • Curated reference: UniProt O05582 (TrEMBL, unreviewed; 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)
  • Model confidence: ESMFold per-residue pLDDT (mean 82.2, confident)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 5 functional partner(s); context anchor Rv0998
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv0999|
MRPPLAPQFAADLLVKTVSTLRSSGAALGRLTTMRKAVLAVGSVCWLVGCSSGASSTTASTGDIAKVAEVKSGFGPEYTVTDVTPRAIDPGFFSARKLPDGLSFDPANCAQVAAGPQLPTGLQGNMAAVSAEGNGNRFVVIAVETSQPLPAPSPGKDCSKVTFSGTQLRGGIEVVDVPHIDGTQTLGVHRVLQAVVGGSARTGELYDYSARFGDYQVIVIANPLVIPGRPVARVDTQRARDLLVQAVAAVRG