infA Resolved · high auto-curated

H37Rv Rv3462c · MTBC0 - · 73 aa · 3880432–3880653 (-) · RefSeq NP_217979.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)translation initiation factor IF-1
MTBC0 PGAP re-annotation
Revised (this work)Translation initiation factor IF-1. Pfam: eIF-1a (PF01176.26).

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 P9WKK3 SwissProt · reviewed · Evidence at protein level
UniProt nameTranslation initiation factor IF-1
Curated functionOne of the essential components for the initiation of protein synthesis. Stabilizes the binding of IF-2 and IF-3 on the 30S subunit to which N-formylmethionyl-tRNA(fMet) subsequently binds. Helps modulate mRNA selection, yielding the 30S pre-initiation complex (PIC). Upon addition of the 50S ribosomal subunit IF-1, IF-2 and IF-3 are released leaving the mature 70S translation initiation complex.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category J Translation, ribosomal structure and biogenesis
Preferred nameinfA
eggNOG descriptionOne of the essential components for the initiation of protein synthesis. Stabilizes the binding of IF-2 and IF-3 on the 30S subunit to which N-formylmethionyl-tRNA(fMet) subsequently binds. Helps modulate mRNA selection, yielding the 30S pre- initiation complex (PIC). Upon addition of the 50S ribosomal subunit IF-1, IF-2 and IF-3 are released leaving the mature 70S translation initation complex
Orthologous groupCOG0361
KEGG orthology K02518
Gene Ontology (20) GO:0003674, GO:0005488, GO:0005575, GO:0005618, GO:0005622, GO:0005623, GO:0005737, GO:0005829, GO:0005886, GO:0008150, GO:0016020, GO:0030312 +8 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 0.0 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 4 synonymous, 0 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
eIF-1aPF01176.26 9.6e-308–71 Translation initiation factor 1A / IF-1

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

Closest characterised functional partner: rpsK (30S ribosomal protein S11), high confidence from genomic context alone (score 1000 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3459c rpsK 30S ribosomal protein S11 999 1000 ctx neighborhood:547 cooccurence:653 coexpression:923 experimental:928 database:547 textmining:452
Rv0682 rpsL 30S ribosomal protein S12 999 999 coexpression:967 experimental:928 database:655
Rv3460c rpsM 30S ribosomal protein S13 999 999 ctx neighborhood:547 cooccurence:493 coexpression:927 experimental:829 database:629 textmining:441
Rv0718 rpsH 30S ribosomal protein S8 999 999 ctx cooccurence:639 coexpression:863 experimental:928 database:659
Rv0702 rplD 50S ribosomal protein L4 998 999 coexpression:865 experimental:928 database:844
Rv0707 rpsC 30S ribosomal protein S3 998 999 ctx cooccurence:656 coexpression:860 experimental:928 database:659
Rv0705 rpsS 30S ribosomal protein S19 998 999 ctx cooccurence:447 coexpression:891 experimental:928 database:659
Rv0700 rpsJ 30S ribosomal protein S10 998 998 coexpression:890 experimental:928 database:652
Rv0710 rpsQ 30S ribosomal protein S17 998 998 ctx cooccurence:527 coexpression:864 experimental:928 database:659
Rv0721 rpsE 30S ribosomal protein S5 998 998 coexpression:864 experimental:928 database:652
Rv3458c rpsD 30S ribosomal protein S4 998 998 ctx neighborhood:508 cooccurence:496 coexpression:767 experimental:928 database:652
Rv0683 rpsG 30S ribosomal protein S7 997 997 coexpression:858 experimental:928 database:652
Rv3461c rpmJ 50S ribosomal protein L36 996 995 ctx neighborhood:812 coexpression:975
Rv2785c rpsO 30S ribosomal protein S15 994 994 coexpression:693 experimental:928 database:652
Rv2890c rpsB 30S ribosomal protein S2 994 993 coexpression:702 experimental:928 database:611

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): translation initiation factor IF-1
  • Pfam (hmmscan --cut_ga): eIF-1a PF01176.26 (E=1e-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_217979.1)
  • Domains: Pfam-A via hmmscan --cut_ga — eIF-1a (PF01176.26)
  • 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 COG0361
  • Curated reference: UniProt P9WKK3 (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 — 139 functional partner(s); context anchor rpsK
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv3462c|infA
MAKKDGAIEVEGRVVEPLPNAMFRIELENGHKVLAHISGKMRQHYIRILPEDRVVVELSPYDLSRGRIVYRYK