nicT Family assigned · medium auto-curated

H37Rv Rv2856 · MTBC0 mtbc0_003035 · 372 aa · 3187350–3188468 (+) · RefSeq NP_217372.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)nickel-transport integral membrane protein NicT
MTBC0 PGAP re-annotationHoxN/HupN/NixA family nickel/cobalt transporter
Revised (this work)HoxN/HupN/NixA family nickel/cobalt transporter. Pfam: NicO (PF03824.23).

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

Curated reference (UniProt)

UniProt I6YEJ7 SwissProt · reviewed · Evidence at protein level
UniProt nameNickel transporter NicT
Curated functionInvolved in nickel uptake. In addition, acts as a drug efflux pump and contributes to moderate tolerance towards different classes of antibiotics, including fluoroquinolones, aminoglycosides and the anti-TB drug isoniazid, with a preference for fluoroquinolones. The drug efflux function is probably dependent on proton motive force (pmf) or ion gradient, and might be facilitated by the presence of Ni(2+) ions.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
Preferred namenicT
eggNOG descriptionBelongs to the NiCoT transporter (TC 2.A.52) family
Orthologous groupCOG2042
KEGG orthology K07241

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 n/a
Polymorphic sites (≥ 0.1% of strains) 0 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
NicOPF03824.23 2.3e-10964–353 High-affinity nickel-transport protein

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

Closest characterised functional partner: mtr (mycothione reductase), medium confidence from genomic context alone (score 662 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2855 mtr mycothione reductase 661 662 ctx neighborhood:657
Rv2854 hyp hypothetical protein 648 648 ctx neighborhood:643
Rv2349c plcC phospholipase C 474 475 ctx cooccurence:467
Rv1902c nanT sialic acid-transport integral membrane protein NanT 471 472 ctx cooccurence:459
Rv2351c plcA membrane-associated phospholipase A 466 467 ctx cooccurence:465
Rv2350c plcB membrane-associated phospholipase B 465 465 ctx cooccurence:462
Rv3310 sapM acid phosphatase 461 461 ctx cooccurence:461
Rv1755c plcD Rv1755c, (MT1799, MTCY28.21c), len: 280 aa. Probable plcD, phospholipase C 4 (fragment) (see citations below),highly similar to C-terminus o 460 461 ctx cooccurence:455
Rv2853 PE_PGRS48 PE-PGRS family protein PE_PGRS48 440 441 ctx neighborhood:441
Rv1762c hyp hypothetical protein 401 401 ctx cooccurence:401
Rv2059 hyp hypothetical protein 642 295 textmining:514
Rv2025c cation efflux system protein 409 241
Rv2060 integral membrane protein 699 174 textmining:651
Rv0106 hyp hypothetical protein 551 114 textmining:515
Rv2359 zur zinc uptake regulation protein 647 87 textmining:630

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: nickel-transport integral membrane protein NicT
  • MTBC0 PGAP product: HoxN/HupN/NixA family nickel/cobalt transporter
  • Pfam (hmmscan --cut_ga): NicO PF03824.23 (E=2e-109)
  • (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_217372.1)
  • Domains: Pfam-A via hmmscan --cut_ga — NicO (PF03824.23)
  • 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 COG2042
  • Curated reference: UniProt I6YEJ7 (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 — 20 functional partner(s); context anchor mtr
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_003035|Rv2856|nicT
MASSQLDRQRSRSAKMNRALTAAEWWRLGLMFAVIVALHLVGWLTVTLLVEPARLSLGGKAFGIGVGLTAYTLGLRHAFDADHIAAIDNTTRKLMSDGHRPLAVGFFFSLGHSTVVFGLAVMLVTGLKAIVGPVENDSSTLHHYTGLIGTSISGAFLYLIGILNVIVLVGIVRVFAHLRRGDYDEAELEQQLDNRGLLIRFLGRFTKSLTKSWHMYPVGFLFGLGFDTATEIALLVLAGTSAAAGLPWYAILCLPVLFAAGMCLLDTIDGSFMNFAYGWAFSSPVRKIYYNITVTGLSVAVALLIGSVELLGLIANQLGWQGPFWDWLGGLDLNTVGFVVVAMFALTWAIALLVWHYGRVEERWTPAPDRTT