rmlB Resolved · high auto-curated

H37Rv Rv3464 · MTBC0 mtbc0_003682 · 331 aa · 3907777–3908772 (+) · RefSeq NP_217981.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)dTDP-glucose 4,6-dehydratase
MTBC0 PGAP re-annotationdTDP-glucose 4%2C6-dehydratase
Revised (this work)DTDP-glucose 4%2C6-dehydratase. Pfam: RmlD_sub_bind (PF04321.24), Polysacc_synt_2 (PF02719.22), GDP_Man_Dehyd (PF16363.12), Epimerase (PF01370.28), 3Beta_HSD (PF01073.26), NAD_binding_4 (PF07993.19), NAD_binding_10 (PF13460.13).

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

Curated reference (UniProt)

UniProt P9WN65 SwissProt · reviewed · Evidence at protein level
UniProt namedTDP-glucose 4,6-dehydratase
EC (curated) EC 4.2.1.46
Curated functionCatalyzes the dehydration of dTDP-D-glucose to form dTDP-6-deoxy-D-xylo-4-hexulose via a three-step process involving oxidation, dehydration and reduction (By similarity). Involved in the biosynthesis of the dTDP-L-rhamnose which is a component of the critical linker, D-N-acetylglucosamine-L-rhamnose disaccharide, which connects the galactan region of arabinogalactan to peptidoglycan via a phosphodiester linkage.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category M Cell wall / membrane / envelope biogenesis
Preferred namermlB
eggNOG descriptionBelongs to the NAD(P)-dependent epimerase dehydratase family. dTDP-glucose dehydratase subfamily
Orthologous groupCOG1088
EC number EC 4.2.1.46
KEGG orthology K01710
KEGG pathways map00521, map00523, map00525, map01055, map01130
KEGG modules M00793
Gene Ontology (67) GO:0000166, GO:0000271, GO:0003674, GO:0003824, GO:0005488, GO:0005575, GO:0005618, GO:0005623, GO:0005975, GO:0005976, GO:0006139, GO:0006725 +55 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 0.147 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 9 synonymous, 4 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
RmlD_sub_bindPF04321.24 6.7e-181–164 RmlD substrate binding domain
Polysacc_synt_2PF02719.22 6.6e-123–122 Polysaccharide biosynthesis protein
GDP_Man_DehydPF16363.12 3.6e-714–303 GDP-mannose 4,6 dehydratase
EpimerasePF01370.28 2.1e-634–238 NAD dependent epimerase/dehydratase family
3Beta_HSDPF01073.26 1.4e-184–160 3-beta hydroxysteroid dehydrogenase/isomerase family
NAD_binding_4PF07993.19 5.1e-125–176 Male sterility protein
NAD_binding_10PF13460.13 1.2e-077–159 NAD(P)H-binding

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

Closest characterised functional partner: rmlC (dTDP-4-dehydrorhamnose 3,5-epimerase), high confidence from genomic context alone (score 999 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3465 rmlC dTDP-4-dehydrorhamnose 3,5-epimerase 999 999 ctx neighborhood:882 fusion:460 cooccurence:663 coexpression:742 database:900 textmining:965
Rv0334 rmlA glucose-1-phosphate thymidylyltransferase 999 995 ctx cooccurence:772 coexpression:734 database:900 textmining:965
Rv3266c rmlD dTDP-4-dehydrorhamnose reductase 989 962 coexpression:715 database:800 textmining:745
Rv3784 dTDP-glucose 4,6-dehydratase 934 922 database:900
Rv0536 galE3 UDP-glucose 4-epimerase GalE 829 822 database:800
Rv0338c iron-sulfur-binding reductase 811 812 coexpression:812
Rv3463 hyp hypothetical protein 792 792 ctx neighborhood:790
Rv1510 hyp hypothetical protein 809 784 coexpression:731
Rv0322 udgA UDP-glucose 6-dehydrogenase UdgA 822 735 coexpression:704
Rv3809c glf UDP-galactopyranose mutase 867 708 coexpression:691 textmining:566
Rv3462c infA translation initiation factor IF-1 681 682 ctx neighborhood:680
Rv3630 integral membrane protein 707 680 coexpression:669
Rv1752 hyp hypothetical protein 685 663 coexpression:644
Rv0501 galE2 UDP-glucose 4-epimerase GalE 640 623 ctx cooccurence:576
Rv3466 hyp hypothetical protein 573 573 ctx neighborhood:571

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: dTDP-glucose 4,6-dehydratase
  • MTBC0 PGAP product: dTDP-glucose 4%2C6-dehydratase
  • Pfam (hmmscan --cut_ga): RmlD_sub_bind PF04321.24 (E=7e-18), Polysacc_synt_2 PF02719.22 (E=7e-12), GDP_Man_Dehyd PF16363.12 (E=4e-71), Epimerase PF01370.28 (E=2e-63), 3Beta_HSD PF01073.26 (E=1e-18), NAD_binding_4 PF07993.19 (E=5e-12), NAD_binding_10 PF13460.13 (E=1e-07)
  • (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_217981.1)
  • Domains: Pfam-A via hmmscan --cut_ga — RmlD_sub_bind (PF04321.24), Polysacc_synt_2 (PF02719.22), GDP_Man_Dehyd (PF16363.12), Epimerase (PF01370.28), 3Beta_HSD (PF01073.26), NAD_binding_4 (PF07993.19), NAD_binding_10 (PF13460.13)
  • 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 COG1088
  • Curated reference: UniProt P9WN65 (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 — 57 functional partner(s); context anchor rmlC
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_003682|Rv3464|rmlB
MRLLVTGGAGFIGTNFVHSAVREHPDDAVTVLDALTYAGRRESLADVEDAIRLVQGDITDAELVSQLVAESDAVVHFAAESHVDNALDNPEPFLHTNVIGTFTILEAVRRHGVRLHHISTDEVYGDLELDDRARFTESTPYNPSSPYSATKAGADMLVRAWVRSYGVRATISNCSNNYGPYQHVEKFIPRQITNVLTGRRPKLYGAGANVRDWIHVDDHNSAVRRILDRGRIGRTYLISSEGERDNLTVLRTLLRLMDRDPDDFDHVTDRVGHDLRYAIDPSTLYDELCWAPKHTDFEEGLRTTIDWYRDNESWWRPLKDATEARYQERGQ