rpiB Resolved · high auto-curated

H37Rv Rv2465c · MTBC0 - · 162 aa · 2767671–2768159 (-) · RefSeq YP_177884.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)ribose-5-phosphate isomerase B
MTBC0 PGAP re-annotation
Revised (this work)Ribose-5-phosphate isomerase B. Pfam: LacAB_rpiB (PF02502.24).

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 P9WKD7 SwissProt · reviewed · Evidence at protein level
UniProt nameRibose-5-phosphate isomerase B
EC (curated) EC 5.3.1.6
Curated functionCatalyzes the interconversion of ribulose-5-P and ribose-5-P. It has not isomerase activity towards D-allose 6-phosphate.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category G Carbohydrate transport and metabolism
Preferred namerpiB
eggNOG descriptionRibose 5-phosphate isomerase
Orthologous groupCOG0698
EC number EC 5.3.1.6
KEGG orthology K01808
KEGG pathways map00030, map00051, map00710, map01100, map01110, map01120, map01130, map01200, map01230
KEGG modules M00004, M00007, M00165, M00167
Gene Ontology (42) GO:0003674, GO:0003824, GO:0004751, GO:0005575, GO:0005576, GO:0006081, GO:0006098, GO:0006139, GO:0006725, GO:0006732, GO:0006733, GO:0006739 +30 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 0.11 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 6 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
LacAB_rpiBPF02502.24 2.7e-456–143 Ribose/Galactose Isomerase

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

Closest characterised functional partner: upp (uracil phosphoribosyltransferase), high confidence from genomic context alone (score 916 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1408 rpe ribulose-phosphate 3-epimerase 941 924 database:900
Rv3309c upp uracil phosphoribosyltransferase 920 916 ctx fusion:899
Rv1449c tkt transketolase 959 913 database:900 textmining:549
Rv1844c gnd1 6-phosphogluconate dehydrogenase 919 908 database:900
Rv2436 rbsK ribokinase RbsK 918 908 database:900
Rv1122 gnd2 6-phosphogluconate dehydrogenase (decarboxylating) 914 908 database:900
Rv1017c prsA ribose-phosphate pyrophosphokinase 928 906 database:900
Rv3068c pgmA phosphoglucomutase PgmA 900 900 database:900
Rv2464c nei1 DNA glycosylase 884 884 ctx neighborhood:882
Rv2466c hyp hypothetical protein 817 818 ctx neighborhood:773
Rv2606c snzP pyridoxine biosynthesis protein 804 804 database:800
Rv2604c snoP glutamine amidotransferase SnoP 800 800 database:800
Rv2029c pfkB 6-phosphofructokinase PfkB 828 775 coexpression:757
Rv2467 pepN aminopeptidase PepN 740 712 ctx neighborhood:708
Rv1093 glyA1 serine hydroxymethyltransferase 629 629 coexpression:401

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): ribose-5-phosphate isomerase B
  • Pfam (hmmscan --cut_ga): LacAB_rpiB PF02502.24 (E=3e-45)
  • (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 YP_177884.1)
  • Domains: Pfam-A via hmmscan --cut_ga — LacAB_rpiB (PF02502.24)
  • 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 COG0698
  • Curated reference: UniProt P9WKD7 (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 — 34 functional partner(s); context anchor upp
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv2465c|rpiB
MSGMRVYLGADHAGYELKQRIIEHLKQTGHEPIDCGALRYDADDDYPAFCIAAATRTVADPGSLGIVLGGSGNGEQIAANKVPGARCALAWSVQTAALAREHNNAQLIGIGGRMHTVAEALAIVDAFVTTPWSKAQRHQRRIDILAEYERTHEAPPVPGAPA