Rv0845 Resolved · high auto-curated

H37Rv Rv0845 · MTBC0 - · 425 aa · 941190–942467 (+) · RefSeq NP_215360.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)sensor histidine kinase NarS
MTBC0 PGAP re-annotation
Revised (this work)Sensor histidine kinase NarS. Pfam: HATPase_c (PF02518.32).

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 O53857 SwissProt · reviewed · Evidence at protein level
UniProt nameSensor histidine kinase NarS
EC (curated) EC 2.7.13.3
Curated functionMember of the two-component regulatory system NarS/NarL involved in gene expression during aerobic nitrate metabolism. Plays therefore a crucial role in anaerobic survival of mycobacteria in host. Functions as a sensor protein kinase which is autophosphorylated at a histidine residue and transfers its phosphate group to the conserved aspartic acid residue in the regulatory domain of NarL. In turn, NarL binds to the upstream promoter regions of target genes to regulate their expression during aerobic nitrate metabolism.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category T Signal transduction mechanisms
eggNOG descriptionHistidine kinase
Orthologous groupCOG4585
EC number EC 2.7.13.3
KEGG orthology K02480

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 1.322 · diversifying/relaxed
Polymorphic sites (≥ 0.1% of strains) 2 synonymous, 7 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
HATPase_cPF02518.32 2.3e-09337–424 Histidine kinase-, DNA gyrase B-, and HSP90-like ATPase

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

Closest characterised functional partner: narL (nitrate/nitrite response transcriptional regulator NarL), high confidence from genomic context alone (score 970 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0844c narL nitrate/nitrite response transcriptional regulator NarL 987 970 ctx neighborhood:783 cooccurence:767 textmining:596
Rv3133c devR two component transcriptional regulator DevR 884 853 ctx cooccurence:726
Rv0195 two component transcriptional regulator 839 818 ctx cooccurence:662
Rv1006 hyp hypothetical protein 617 617 ctx cooccurence:615
Rv2047c hyp hypothetical protein 625 602 ctx cooccurence:597
Rv0890c HTH-type transcriptional regulator 592 573
Rv1358 transcriptional regulator 574 554
Rv2488c LuxR family transcriptional regulator 572 553
Rv0386 transcriptional regulator 572 553
Rv1868 hyp hypothetical protein 526 527 ctx cooccurence:526
Rv1435c hyp hypothetical protein 522 522 ctx cooccurence:518
Rv2862c hyp hypothetical protein 520 500 coexpression:483
Rv0966c hyp hypothetical protein 519 499 coexpression:482
Rv1118c hyp hypothetical protein 490 467
Rv0339c iniR transcriptional regulator 490 466

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): sensor histidine kinase NarS
  • Pfam (hmmscan --cut_ga): HATPase_c PF02518.32 (E=2e-09)
  • (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_215360.1)
  • Domains: Pfam-A via hmmscan --cut_ga — HATPase_c (PF02518.32)
  • 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 COG4585
  • Curated reference: UniProt O53857 (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 — 31 functional partner(s); context anchor narL
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv0845|
MPSYGNLGRLGGRHEYGVLVAMTSSAELDRVRWAHQLRSYRIASVLRIGVVGLMVAAMVVGTSRSEWPQQIVLIGVYAVAALWALLLAYSASRRFFALRRFRSMGRLEPFAFTAVDVLILTGFQLLSTDGIYPLLIMILLPVLVGLDVSTRRAAVVLACTLVGFAVAVLGDPVMLRAIGWPETIFRFALYAFLCATALMVVRIEERHTRSVAGLSALRAELLAQTMTASEVLQRRIAEAIHDGPLQDVLAARQELIELDAVTPGDERVGRALAGLQSASERLRQATFELHPAVLEQVGLGPAVKQLAASTAQRSGIKISTDIDYPIRSGIDPIVFGVVRELLSNVVRHSGATTASVRLGITDEKCVLDVADDGVGVTGDTMARRLGEGHIGLASHRARVDAAGGVLVFLATPRGTHVCVELPLKR