Rv2998A Family assigned · low auto-curated · to review

H37Rv Rv2998A · MTBC0 · 67 aa · 3357225–3357428 H37Rv (-) · RefSeq

Genomic neighbourhood (genome browser)

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Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)Conserved hypothetical protein
MTBC0 PGAP re-annotation
Functional category (TubercuList)conserved hypotheticals

Curation note: Added P16.5d: Mycobrowser-annotated gene absent from RefSeq NC_000962.3 (the atlas' original 3906-CDS reference). Foundation record from the Mycobrowser release + translated H37Rv sequence; heavy enrichment layers (structure, orthology, conservation, interaction) pending.

Auto-curated: this verdict and function were generated by rules from PGAP + Pfam + Foldseek and have not been hand-reviewed (flagged for human review).

In the literature (TB corpus sweep)

This distinguishes a gene that is dark because nobody has looked from one that is dark despite having been studied. Source: .

Legacy record & comparison (Mycobrowser)

Mycobrowser functionFunction unknown

The legacy Mycobrowser record is shown for verification. Mycobrowser is no longer maintained; its EC numbers predate recent nomenclature revisions, so a class change usually reflects re-numbering, not a conflict.

Curated reference (UniProt)

UniProt Q6MX20 TrEMBL · unreviewed
UniProt namehistidine kinase
EC (curated) EC 2.7.13.3

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category T Signal transduction mechanisms
eggNOG descriptionHAMP (Histidine kinases, Adenylyl cyclases, Methyl binding proteins, Phosphatases) domain
Orthologous groupCOG0642

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 0.0 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 1 synonymous, 0 missense, 0 nonsense, 1 frameshift
Disruption 1 distinct premature-stop/frameshift site(s); most common in 0.11% of strains (161) · 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.

Essentiality (transposon mutagenesis)

DeJesus 2017 callUncertain · uncertain
What the call meansuncertain (short or TA-poor ORF): no call possible
TA sites (Himar1) 2 in the ORF — 0 in the essential state, 0 growth-defect, 2 non-essential, 0 growth-advantage. Saturation 0.500, mean read count 5. A region of the protein devoid of TA sites is invisible to this assay: nothing can be inferred about it, in either direction.
CaveatStatistically thin call: only 2 TA (Himar1) sites in the whole ORF (atlas median 13; genes under 300 nt typically have very few). A DeJesus 2017 call built on so few independent observations is less robust than the same call on a longer gene, in either direction. Cross-check against the CRISPRi vulnerability index (independent of TA-site density) and, if this gene overlaps a neighbour (see Genomic-neighbour overlap section below), verify how many of its TA sites actually fall inside its own ORF. (P20.3)

Genome-wide Himar1 transposon essentiality in H37Rv (DeJesus 2017). An essential call (ES/ESD/GD) is strong, independent evidence that a "hypothetical" locus encodes a functional, selectively required gene — orthogonal to intra-species conservation.

Proteomics (mass spectrometry) not detected

Not detected in the mass-spectrometry datasets integrated by PaxDb. This is not evidence of absence: low-abundance, condition-specific, or MS-refractory proteins (e.g. small, highly hydrophobic, or repetitive PE/PPE families with few tryptic peptides) are systematically under-sampled.

Physico-chemical properties (computed, ProtParam)

Length67 aa
Molecular weight7.6 kDa
Theoretical pI6.92
GRAVY-0.488 (hydrophilic)
Aliphatic index96.3
Aromaticity0.045
Instability index32.8 (stable)

Computed from the ancestral MTBC0 sequence with the ExPASy ProtParam method (Biopython). Descriptive biophysical context: a positive GRAVY flags a hydrophobic (often membrane) protein, a high instability index (>40) predicts a short in-vitro half-life, an extreme pI hints at compartment or binding partner.

Domains (Pfam, hmmscan --cut_ga)

No Pfam-A domain above the gathering threshold (or not yet scanned).

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

Explore full network →

Node colour = verdict, dashed = hypothetical; edge colour = evidence (green experimental, orange genomic-context, grey co-expression), width ∝ score. Click a partner to open its page; "Explore full network" to walk the graph.

Closest characterised functional partner: tcrA (two component DNA binding transcriptional regulator TcrA), high confidence from genomic context alone (score 751 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv0602c tcrA two component DNA binding transcriptional regulator TcrA 759 751 ctx cooccurence:408
Rv1248c kgd exp multifunctional 2-oxoglutarate dehydrogenase E1 component /2-oxoglutarate dehydrogenase dihydrolipoyllysine-residue succinyltransferase 757 728 experimental:422 database:538
Rv2496c bkdB exp 3-methyl-2-oxobutanoate dehydrogenase subunit beta 742 728 database:590
Rv1734c hyp exp hypothetical protein 726 715 experimental:401 database:538
Rv2215 dlaT exp pyruvate dehydrogenase E2 component dihydrolipoamide acyltransferase 725 715 experimental:401 database:538
Rv2495c bkdC exp branched-chain keto acid dehydrogenase E2 component 724 713 experimental:401 database:538
Rv1017c prsA exp ribose-phosphate pyrophosphokinase 712 696 database:586
Rv0981 mprA two-component response regulator MrpA 666 654
Rv1033c trcR two component transcriptional regulator TrcR 652 640
Rv0757 phoP two component system response transcriptional positive regulator PhoP 649 636
Rv3765c tcrX two component transcriptional regulator TcrX 644 631
Rv2299c htpG exp chaperone protein HtpG 627 604 database:537
Rv0794c exp oxidoreductase 610 594 database:527
Rv2713 sthA exp pyridine nucleotide transhydrogenase 607 591 database:527
Rv3303c lpdA exp NAD(P)H quinone reductase LpdA 606 589 database:527

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 exp badge marks an experimentally-supported partner (measured interaction, experimental/database channel ≥400) as opposed to a purely predicted one — but note that the M. tuberculosis experimental interactome is dominated by a noisy bacterial-two-hybrid screen, so a strong measured link that contradicts the operon/localisation context is likely a false positive. 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.

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 )
  • Domains: Pfam-A via hmmscan --cut_ga — none above threshold
  • 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 COG0642
  • Curated reference: UniProt Q6MX20 (TrEMBL, unreviewed)
  • Intra-MTBC selection: pN/pS and disruption from SPDI variants of 145 209 MTBC strains (this work, local collection vs H37Rv NC_000962.3)
  • Genome-wide structure: AlphaFold DB model (Jumper et al. 2021, doi:10.1038/s41586-021-03819-2; Varadi et al. 2024, doi:10.1093/nar/gkad1011) searched vs PDB with Foldseek (mean pLDDT 91.1)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 52 functional partner(s); context anchor tcrA
  • Essentiality: genome-wide transposon mutagenesis in H37Rv — DeJesus et al. 2017 (mBio, doi:10.1128/mBio.02133-16, CC BY)
  • Functional category: TubercuList scheme (Cole et al. 1998, doi:10.1038/31159), via Mycobrowser (Kapopoulou et al. 2011, doi:10.1016/j.tube.2010.09.006)
  • Physico-chemical properties: ExPASy ProtParam method via Biopython (Gasteiger et al. 2005), computed from the MTBC0 sequence
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>|Rv2998A|Rv2998A
VERMRIRAAGISATDPHARLPLPLARDEIRYLGTTFNDLLQRLQDALERERQFVSDAGHELRTPLAS