recB Family assigned · medium auto-curated

H37Rv Rv0630c · MTBC0 mtbc0_000663 · 1094 aa · 725282–728566 (-) · RefSeq NP_215144.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)exonuclease V subunit beta RecB
MTBC0 PGAP re-annotationexodeoxyribonuclease V subunit beta
Revised (this work)Exodeoxyribonuclease V subunit beta. Pfam: UvrD-helicase (PF00580.28), AAA_19 (PF13245.13), UvrD_C (PF13361.13), PDDEXK_1 (PF12705.14).

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

Curated reference (UniProt)

UniProt P9WMQ3 SwissProt · reviewed · Evidence at protein level
UniProt nameRecBCD enzyme subunit RecB
EC (curated) EC 3.1.11.5, EC 5.6.2.4
Curated functionA helicase/nuclease that prepares dsDNA breaks (DSB) for recombinational DNA repair. Binds to DSBs and unwinds DNA via a highly rapid and processive ATP-dependent bidirectional helicase activity. In the holoenzyme this subunit contributes ATPase, 3'-5' helicase, exonuclease activity and loads RecA onto ssDNA. Unlike the case in E.coli, suppresses RecA-dependent homologous recombination, is instead required for single-strand annealing pathway repair of DSB.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category L Replication, recombination and repair
Preferred namerecB
eggNOG descriptionA helicase nuclease that prepares dsDNA breaks (DSB) for recombinational DNA repair. Binds to DSBs and unwinds DNA via a highly rapid and processive ATP-dependent bidirectional helicase activity. Unwinds dsDNA until it encounters a Chi (crossover hotspot instigator) sequence from the 3' direction. Cuts ssDNA a few nucleotides 3' to the Chi site. The properties and activities of the enzyme are changed at Chi. The Chi-altered holoenzyme produces a long 3'-ssDNA overhang and facilitates RecA-binding to the ssDNA for homologous DNA recombination and repair. Holoenzyme degrades any linearized DNA that is unable to undergo homologous recombination. In the holoenzyme this subunit contributes ATPase, 3'-5' helicase, exonuclease activity and loads RecA onto ssDNA
Orthologous groupCOG1074
EC number EC 3.1.11.5
KEGG orthology K03582
KEGG pathways map03440
Gene Ontology (13) GO:0005575, GO:0005618, GO:0005622, GO:0005623, GO:0005737, GO:0005829, GO:0005886, GO:0016020, GO:0030312, GO:0044424, GO:0044444, GO:0044464 +1 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) pseudogene candidate

pN/pS 0.341 · purifying
Polymorphic sites (≥ 0.1% of strains) 27 synonymous, 25 missense, 0 nonsense, 1 frameshift
Disruption 1 distinct premature-stop/frameshift site(s); most common in 10.04% of strains (14578) · clonal

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
UvrD-helicasePF00580.28 1.3e-5614–310 UvrD/REP helicase N-terminal domain
AAA_19PF13245.13 8.3e-1515–299 AAA domain
UvrD_CPF13361.13 1.2e-06595–686 UvrD-like helicase C-terminal domain
PDDEXK_1PF12705.14 7.5e-07831–1052 PD-(D/E)XK nuclease superfamily

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

Closest characterised functional partner: recC (exonuclease V subunit gamma RecC), high confidence from genomic context alone (score 998 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0631c recC exonuclease V subunit gamma RecC 999 998 ctx neighborhood:881 cooccurence:774 experimental:829 textmining:831
Rv0629c recD exonuclease V subunit alpha RecD 998 996 ctx neighborhood:881 cooccurence:773 coexpression:460 experimental:510 database:540 textmining:707
Rv2311 hyp hypothetical protein 649 602 experimental:510
Rv0628c hyp hypothetical protein 554 554 ctx neighborhood:553
Rv2037c transmembrane protein 513 513 ctx neighborhood:511
Rv0955 integral membrane protein 467 468 ctx cooccurence:422
Rv1407 fmu 16S rRNA m5C967 methyltransferase 444 444
Rv0632c echA3 enoyl-CoA hydratase EchA3 432 432 ctx neighborhood:432
Rv2529 hyp hypothetical protein 408 408 ctx cooccurence:400
Rv3370c dnaE2 error-prone DNA polymerase 614 374 textmining:409
Rv1547 dnaE1 DNA polymerase III subunit alpha 520 373
Rv2737c recA recombinase A 823 357 textmining:737
Rv3014c ligA DNA ligase A 761 348 textmining:649
Rv0058 dnaB replicative DNA helicase 646 334 textmining:491
Rv1629 polA DNA polymerase I 809 278 textmining:747

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: exonuclease V subunit beta RecB
  • MTBC0 PGAP product: exodeoxyribonuclease V subunit beta
  • Pfam (hmmscan --cut_ga): UvrD-helicase PF00580.28 (E=1e-56), AAA_19 PF13245.13 (E=8e-15), UvrD_C PF13361.13 (E=1e-06), PDDEXK_1 PF12705.14 (E=8e-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_215144.1)
  • Domains: Pfam-A via hmmscan --cut_ga — UvrD-helicase (PF00580.28), AAA_19 (PF13245.13), UvrD_C (PF13361.13), PDDEXK_1 (PF12705.14)
  • 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 COG1074
  • Curated reference: UniProt P9WMQ3 (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 — 47 functional partner(s); context anchor recC
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_000663|Rv0630c|recB
MDRFELLGPLPREGTTTVLEASAGTGKTFALAGLVTRYLAETAATLDEMLLITFNRAASRELRERVRGQIVEAVGALQGDAPPSGELVEHLLRGSDAERAQKRSRLRDALANFDAATIATTHEFCGSVLKSLGVAGDNAADVELKESLTDLVTEIVDDRYLANFGRQETDPELTYAEALALALAVVDDPCAQLRPPDPEPGSKAAVRLRFAAEVLEELERRKGRLRAQGFNDLLIRLATALEAADSPARDRMRERWRIVLVDEFQDTDPMQWRVLERAFSRHSALILIGDPKQAIYGFRGGDIHTYLKAAGTADARYTLGVNWRSDRALVESLQTVLRDATLGHADIVVRGTDAHHAGHRLASAPRPAPFRLRVVKRHTLGYDGTAHVPIEALRRHIPDDLAADVAALLASGATFAGRPVVAADIAVIVEHHKDARACRNALAEAGIPAIYTGDTDVFASQAAKDWLCLLEAFDAPQRSGLVRAAACTMFFGETAESLAAEGDALTDRVAGTLREWADHARHRGVAAVFQAAQLAGMGRRVLSQRGGERDLTDLAHIAQLLHEAAHRERLGLPGLRDWLRRQAKAGAGPPEHNRRLDSDAAAVQIMTVFVAKGLQFPIVYLPFAFNRNVRSDDILLYHDDGTRCLYIGGKDGGAQRRTVEGLNRVEAAHDNLRLTYVALTRAQSQVVAWWAPTFDEVNGGLSRLLRGRRPGQSQVPDRCTPRVTDEQAWAVFAQWEAAGGPSVEESVIGARSSLEKPVPVPGFEVRHFHRRIDTTWRRTSYSDLVRGSEAVTVTSEPAAGGRADEVEIAVVAAPGSGADLTSPLAALPSGASFGSLVHAVLETADPAAPDLAAELEAQVRRHAPWWTVDVDHAQLAPELARALLPMHDTPLGPAAAALTLRQIGVRDRLRELDFEMPLAGGDLRGRSPDVSLADVGELLASHLPGDDPLSPYADRLGSAGLGDQPLRGYLAGSIDVVLRLPGQRYLVVDYKTNHLGDTAADYGFERLTEAMLHSDYPLQALLYVVVLHRFLRWRQRDYAPARHLGGVLYLFVRGMCGAATPVTAGHPAGVFTWNPPTALVVALSDLLDRGRLQS