scpB Family assigned · medium auto-curated

H37Rv Rv1710 · MTBC0 mtbc0_001820 · 231 aa · 1950161–1950856 (+) · RefSeq NP_216226.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)segregation and condensation protein ScpB
MTBC0 PGAP re-annotationSMC-Scp complex subunit ScpB
Revised (this work)SMC-Scp complex subunit ScpB. Pfam: SMC_ScpB (PF04079.23).

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

Curated reference (UniProt)

UniProt I6XCB2 TrEMBL · unreviewed · Evidence at protein level
UniProt namePossible segregation and condensation protein ScpB

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category D Cell cycle control, cell division, chromosome partitioning
Preferred namescpB
eggNOG descriptionParticipates in chromosomal partition during cell division. May act via the formation of a condensin-like complex containing Smc and ScpA that pull DNA away from mid-cell into both cell halves
Orthologous groupCOG1386
KEGG orthology K06024

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 0.358 · purifying
Polymorphic sites (≥ 0.1% of strains) 1 synonymous, 1 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
SMC_ScpBPF04079.23 1.3e-4531–188 Segregation and condensation complex subunit ScpB

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

Closest characterised functional partner: scpA (segregation and condensation protein ScpA), high confidence from genomic context alone (score 1000 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1709 scpA segregation and condensation protein ScpA 999 1000 ctx neighborhood:881 cooccurence:773 coexpression:944 experimental:928 textmining:957
Rv1712 cmk cytidylate kinase 990 983 ctx neighborhood:881 coexpression:829 textmining:489
Rv1711 RNA pseudouridine synthase 988 977 ctx neighborhood:881 coexpression:814 textmining:509
Rv1713 engA GTPase Der 981 971 ctx neighborhood:881 coexpression:723
Rv1708 initiation inhibitor protein 923 919 ctx neighborhood:882
Rv2922c smc chromosome partition protein Smc 938 814 ctx cooccurence:770 textmining:681
Rv1707 transmembrane protein 756 757 ctx neighborhood:757
Rv1703c methyltransferase 709 709 ctx neighborhood:544
Rv1714 oxidoreductase 518 519 ctx neighborhood:489
Rv1716 hyp hypothetical protein 496 496 ctx neighborhood:489
Rv1715 fadB3 3-hydroxybutyryl-CoA dehydrogenase FadB 496 495 ctx neighborhood:488
Rv2155c murD UDP-N-acetylmuramoylalanine--D-glutamate ligase 490 490 coexpression:461
Rv1717 hyp hypothetical protein 484 484 ctx neighborhood:476
Rv1706A hyp hypothetical protein 460 459 ctx neighborhood:459
Rv2786c ribF bifunctional riboflavin kinase /FMN adenylyltransferase 459 459 coexpression:442

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: segregation and condensation protein ScpB
  • MTBC0 PGAP product: SMC-Scp complex subunit ScpB
  • Pfam (hmmscan --cut_ga): SMC_ScpB PF04079.23 (E=1e-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 NP_216226.1)
  • Domains: Pfam-A via hmmscan --cut_ga — SMC_ScpB (PF04079.23)
  • 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 COG1386
  • Curated reference: UniProt I6XCB2 (TrEMBL, unreviewed; 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 — 35 functional partner(s); context anchor scpA
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_001820|Rv1710|scpB
MTEHMPEHDPSYGIPDIAEPAELDADELKRVLEALLLVIDTPVTADALAAATEQPVYRVAAKLQLMADELTGRDSGIDLRHTSEGWRMYTRARFAPYVEKLLLDGARTKLTRAALETLAVVAYRQPVTRARVSAVRGVNVDAVMRTLLARGLITEVGTDADTGAVTFATTELFLERLGLTSLSELPDIAPLLPDVDTIDDLSESLDSEPRFIKLTGELASEQTLSFDVDRD