pitB Resolved · high auto-curated

H37Rv Rv2281 · MTBC0 mtbc0_002422 · 552 aa · 2577920–2579578 (+) · RefSeq NP_216797.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)phosphate permease
MTBC0 PGAP re-annotationanion permease
Revised (this work)Anion permease. Pfam: PHO4 (PF01384.26).

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

Curated reference (UniProt)

UniProt P9WIA5 SwissProt · reviewed · Inferred from homology
UniProt namePutative phosphate permease Rv2281
Curated functionPotential transporter for phosphate.

UniProt still lists this protein as Putative phosphate permease Rv2281; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category P Inorganic ion transport and metabolism
Preferred namepitB
eggNOG descriptionPhosphate transporter family
Orthologous groupCOG0306
KEGG orthology K03306
Gene Ontology (33) GO:0003674, GO:0005215, GO:0005315, GO:0005575, GO:0005623, GO:0005886, GO:0005887, GO:0006810, GO:0006811, GO:0006817, GO:0006820, GO:0008150 +21 more

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 0.242 · purifying
Polymorphic sites (≥ 0.1% of strains) 7 synonymous, 5 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
PHO4PF01384.26 4.8e-10884–541 Phosphate transporter family

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

Closest characterised functional partner: Rv2280 (Rv2280, (MTCY339.30c), len: 459 aa. Probable dehydrogenase. Similar to D-lactate dehydrogenase (cytochrome) precursor e.g. G1061264 (587 aa)), medium confidence from genomic context alone (score 484 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2847c cysG multifunctional uroporphyrin-III C-methyltransferase/precorrin-2 oxidase/ferrochelatase 569 507 coexpression:440
Rv2280 Rv2280, (MTCY339.30c), len: 459 aa. Probable dehydrogenase. Similar to D-lactate dehydrogenase (cytochrome) precursor e.g. G1061264 (587 aa) 484 484 ctx neighborhood:459
Rv1640c lysX bifunctional lysine--tRNA ligase/phosphatidylglycerol lysyltransferase 458 458 coexpression:444
Rv2883c pyrH uridylate kinase 421 422 coexpression:421
Rv3598c lysS lysine--tRNA ligase 417 417 coexpression:415
Rv1286 cysC adenylyl-sulfate kinase 432 354
Rv3232c ppk2 polyphosphate kinase 410 350
Rv0545c pitA low-affinity inorganic phosphate transporter 480 311
Rv3859c gltB glutamate synthase large subunit 579 110 textmining:547
Rv0935 pstC1 phosphate ABC transporter permease PstC 507 76 textmining:489
Rv0933 pstB phosphate ABC transporter ATP-binding protein PstB 515 73 textmining:499
Rv0934 pstS1 phosphate ABC transporter substrate-binding lipoprotein PstS 414 73
Rv0819 mshD mycothiol acetyltransferase 421 69 textmining:404

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: phosphate permease
  • MTBC0 PGAP product: anion permease
  • Pfam (hmmscan --cut_ga): PHO4 PF01384.26 (E=5e-108)
  • (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_216797.1)
  • Domains: Pfam-A via hmmscan --cut_ga — PHO4 (PF01384.26)
  • 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 COG0306
  • Curated reference: UniProt P9WIA5 (SwissProt, reviewed; Inferred from homology)
  • 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 — 13 functional partner(s); context anchor Rv2280
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_002422|Rv2281|pitB
MSDNAKHHRDGHLVASGLQDRAARTPQHEGFLGPDRPWHLSFSLLLAGSFVLFSWWAFDYAGSGANKVILVLATVVGMFMAFNVGGNDVANSFGTSVGAGTLTMKQALLVAAIFEVSGAVIAGGDVTETIRSGIVDLSGVSVDPRDFMNIMLSALSAAALWLLFANRMGYPVSTTHSIIGGIVGAAIALGMVSGQGGAALRMVQWDQIGQIVVSWVLSPVLGGLVSYLLYGVIKRHILLYNEQAERRLTEIKKERIAHRERHKAAFDRLTEIQQIAYTGALARDAVAANRKDFDPDELESDYYRELHEIDAKTSSVDAFRALQNWVPLVAAAGSMIIVAMLLFKGFKHMHLGLTTMNNYFIIAMVGAAVWMATFIFAKTLRGESLSRSTFLMFSWMQVFTASGFAFSHGSNDIANAIGPFAAILDVLRTGAIEGNAAVPAAAMVTFGVALCAGLWFIGRRVIATVGHNLTTMHPASGFAAELSAAGVVMGATVLGLPVSSTHILIGAVLGVGIVNRSTNWGLMKPIVLAWVITLPSAAILASVGLVALRAIF