Rv1989c Family assigned · medium auto-curated

H37Rv Rv1989c · MTBC0 mtbc0_002113 · 186 aa · 2256352–2256912 (-) · RefSeq NP_216505.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotationRES family NAD+ phosphorylase
Revised (this work)RES family NAD+ phosphorylase. Pfam: RES (PF08808.18).

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

Curated reference (UniProt)

UniProt P9WLP9 SwissProt · reviewed · Evidence at protein level
UniProt nameNAD(+) phosphorylase MbcT
EC (curated) EC 2.4.2.-
Curated functionToxic component of a type II toxin-antitoxin (TA) system. Neutralized by cognate antitoxin MbcA. Degrades NAD(+) by phosphorolysis. Expression in the absence of its cognate antitoxin MbcA causes dramatic reduction of intracellular NAD(+) levels and is deleterious to cell growth, causing cell death. In a SCID mouse infection model, mice infected with bacteria overexpressing this protein survive longer. Overexpression of this protein in a mouse infection model at 21 days leads to bacterial death, and shows a synergistic 100-fold increase in mouse survival when combined with isoniazid treatment.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
eggNOG descriptionRES
Orthologous groupCOG5654

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 0.682 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 1 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
RESPF08808.18 8.8e-1825–148 RES domain

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

Closest characterised functional partner: mbcA (transcriptional regulator), high confidence from genomic context alone (score 1000 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv1990c mbcA transcriptional regulator 999 1000 ctx neighborhood:882 experimental:999 textmining:870
Rv3188 hyp hypothetical protein 985 959 experimental:956 textmining:652
Rv1990A Rv1990A, len: 111 aa. Possible dehydrogenase (fragment), similar to N-terminal part of several dehydrogenases and hypothetical proteins, e.g 454 454 ctx neighborhood:425
Rv2034 ArsR family HTH-type transcriptional repressor 457 83 textmining:433
Rv1330c pncB1 nicotinic acid phosphoribosyltransferase PncB1 422 61 textmining:410
Rv3189 hyp hypothetical protein 658 55 textmining:653
Rv2035 hyp hypothetical protein 546 55 textmining:540
Rv1985c lysG HTH-type transcriptional regulator 445 55 textmining:437
Rv0837c hyp hypothetical protein 437 52 textmining:431
Rv0918 hyp hypothetical protein 652 47 textmining:650
Rv1981c nrdF1 ribonucleoside-diphosphate reductase subunit beta NrdF1 632 47 textmining:630
Rv3698 hyp hypothetical protein 626 47 textmining:624
Rv3697c vapC48 ribonuclease VapC48 512 46 textmining:510
Rv1545 hyp hypothetical protein 414 46 textmining:411
Rv1978 hyp hypothetical protein 513 45 textmining:511

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: RES family NAD+ phosphorylase
  • Pfam (hmmscan --cut_ga): RES PF08808.18 (E=9e-18)
  • (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_216505.1)
  • Domains: Pfam-A via hmmscan --cut_ga — RES (PF08808.18)
  • 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 COG5654
  • Curated reference: UniProt P9WLP9 (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 mbcA
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_002113|Rv1989c|
MSDALDEGLVQRIDARGTIEWSETCYRYTGAHRDALSGEGARRFGGRWNPPLLFPAIYLADSAQACMVEVERAAQAASTTAEKMLEAAYRLHTIDVTDLAVLDLTTPQAREAVGLENDDIYGDDWSGCQAVGHAAWFLHMQGVLVPAAGGVGLVVTAYEQRTRPGQLQLRQSVDLTPALYQELRAT