irtA Family assigned · medium auto-curated

H37Rv Rv1348 · MTBC0 mtbc0_001446 · 859 aa · 1523749–1526328 (+) · RefSeq NP_215864.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)iron ABC transporter ATP-binding protein/permease IrtA
MTBC0 PGAP re-annotationiron ABC transporter ATP-binding protein/permease IrtA
Revised (this work)Iron ABC transporter ATP-binding protein/permease IrtA. Pfam: FAD_binding_9 (PF08021.18), SIP (PF04954.19), ABC_membrane (PF00664.29), ABC_tran (PF00005.34).

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

Curated reference (UniProt)

UniProt P9WQJ9 SwissProt · reviewed · Evidence at protein level
UniProt nameMycobactin import ATP-binding/permease protein IrtA
EC (curated) EC 7.2.2.-
Curated functionPart of the ABC transporter complex IrtAB involved in the import of iron-bound mycobactin (Fe-MBT) and carboxymycobactin (Fe-cMBT) (By similarity). Mycobactins are then reduced by the siderophore interaction domain to facilitate iron release in the bacterial cell (By similarity). Transmembrane domains (TMD) form a pore in the membrane and the ATP-binding domain (NBD) is responsible for energy generation (By similarity). Required for replication in human macrophages and in mouse lungs.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category P Inorganic ion transport and metabolism
V Defense mechanisms
Preferred nameirtA
eggNOG descriptionABC transporter
Orthologous groupCOG1132
KEGG orthology K06147, K14698
KEGG pathways map02010
Gene Ontology (88) GO:0000041, GO:0000166, GO:0003674, GO:0005215, GO:0005488, GO:0005575, GO:0005623, GO:0005886, GO:0006810, GO:0006811, GO:0006812, GO:0006826 +76 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 0.288 · purifying
Polymorphic sites (≥ 0.1% of strains) 9 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
FAD_binding_9PF08021.18 2.1e-1060–113 Siderophore-interacting FAD-binding domain
SIPPF04954.19 2.4e-26130–241 Siderophore-interacting protein
ABC_membranePF00664.29 7.9e-16294–553 ABC transporter transmembrane region
ABC_tranPF00005.34 9.4e-29627–774 ABC transporter

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

Closest characterised functional partner: irtB (iron ABC transporter ATP-binding protein/permease IrtB), high confidence from genomic context alone (score 998 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1349 irtB iron ABC transporter ATP-binding protein/permease IrtB 999 998 ctx neighborhood:833 coexpression:861 database:900 textmining:623
Rv2383c mbtB phenyloxazoline synthase 979 919 ctx neighborhood:544 coexpression:757 textmining:756
Rv2384 mbtA 2,3-dihydroxybenzoate-AMP ligase 956 896 coexpression:853 textmining:596
Rv2386c mbtI salicylate synthase 909 796 coexpression:751 textmining:577
Rv3402c hyp hypothetical protein 831 787 coexpression:780
Rv0435c ATPase 773 745 database:528
Rv0282 eccA3 ESX-3 secretion system protein EccA 855 716 database:528 textmining:511
Rv0350 dnaK chaperone protein DnaK 730 702 ctx cooccurence:471
Rv1350 fabG2 3-oxoacyl-ACP reductase FabG 692 678 ctx neighborhood:506
Rv3884c eccA2 ESX-2 secretion system protein EccA 705 663 database:528
Rv3868 eccA1 ESX-1 secretion system protein EccA1 749 662 database:528
Rv2688c antibiotic ABC transporter ATP-binding protein 667 647 database:536
Rv3846 sodA superoxide dismutase 663 643 experimental:412
Rv2378c mbtG L-lysine N6-monooxygenase 767 638 ctx cooccurence:546
Rv1687c ABC transporter ATP-binding protein 654 632 database:536

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: iron ABC transporter ATP-binding protein/permease IrtA
  • MTBC0 PGAP product: iron ABC transporter ATP-binding protein/permease IrtA
  • Pfam (hmmscan --cut_ga): FAD_binding_9 PF08021.18 (E=2e-10), SIP PF04954.19 (E=2e-26), ABC_membrane PF00664.29 (E=8e-16), ABC_tran PF00005.34 (E=9e-29)
  • (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_215864.1)
  • Domains: Pfam-A via hmmscan --cut_ga — FAD_binding_9 (PF08021.18), SIP (PF04954.19), ABC_membrane (PF00664.29), ABC_tran (PF00005.34)
  • 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 COG1132
  • Curated reference: UniProt P9WQJ9 (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 — 151 functional partner(s); context anchor irtB
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_001446|Rv1348|irtA
MARGLQGVMLRSFGARDHTATVIETISIAPHFVRVRMVSPTLFQDAEAEPAAWLRFWFPDPNGSNTEFQRAYTISEADPAAGRFAVDVVLHDPAGPASSWARTVKPGATIAVMSLMGSSRFDVPEEQPAGYLLIGDSASIPGMNGIIETVPNDVPIEMYLEQHDDNDTLIPLAKHPRLRVRWVMRRDEKSLAEAIENRDWSDWYAWATPEAAALKCVRVRLRDEFGFPKSEIHAQAYWNAGRAMGTHRATEPAATEPEVGAAPQPESAVPAPARGSWRAQAASRLLAPLKLPLVLSGVLAALVTLAQLAPFVLLVELSRLLVSGAGAHRLFTVGFAAVGLLGTGALLAAALTLWLHVIDARFARALRLRLLSKLSRLPLGWFTSRGSGSIKKLVTDDTLALHYLVTHAVPDAVAAVVAPVGVLVYLFVVDWRVALVLFGPVLVYLTITSSLTIQSGPRIVQAQRWAEKMNGEAGSYLEGQPVIRVFGAASSSFRRRLDEYIGFLVAWQRPLAGKKTLMDLATRPATFLWLIAATGTLLVATHRMDPVNLLPFMFLGTTFGARLLGIAYGLGGLRTGLLAARHLQVTLDETELAVREHPREPLDGEAPATVVFDHVTFGYRPGVPVIQDVSLTLRPGTVTALVGPSGSGKSTLATLLARFHDVERGAIRVGGQDIRSLAADELYTRVGFVLQEAQLVHGTAAENIALAVPDAPAEQVQVAAREAQIHDRVLRLPDGYDTVLGANSGLSGGERQRLTIARAILGDTPVLILDEATAFADPESEYLVQQALNRLTRDRTVLVIAHRLHTITRADQIVVLDHGRIVERGTHEELLAAGGRYCRLWDTGQGSRVAVAAAQDGTR