Rv1957 Resolved · medium auto-curated
H37Rv Rv1957 · MTBC0 mtbc0_002072 ·
181 aa · 2221700–2222245 (+) ·
RefSeq NP_216473.1
Annotation: from legacy to revised
| Legacy (H37Rv / Mycobrowser) | SecB-like chaperone |
|---|---|
| MTBC0 PGAP re-annotation | SecB-like chaperone |
| Revised (this work) | SecB-like chaperone. |
Auto-curated: this verdict and function were generated by rules from PGAP + Pfam + Foldseek and have not been hand-reviewed.
Curated reference (UniProt)
| UniProt |
P95257
SwissProt · reviewed
· Evidence at protein level
|
|---|---|
| UniProt name | SecB-like chaperone Rv1957 |
| Curated function | Chaperone component of an atypical, type II toxin-antitoxin chaperone (TAC) system. Prevents antitoxin HigA1 aggregation in vitro at a 1:3 chaperone:antitoxin ratio, probably also protects antitoxin HigA1 from protease. Required for neutralization of toxin HigB1 upon ectopic expression in Mycobacterium marinum or E.coli. When expressed in E.coli complements a secB deletion, restores export of OmpA and MBP and inhibits aggregation of proOmpC although it is less efficient than endogenous SecB. Complements the general chaperone function of E.coli SecB less well. |
Functional vocabulary (eggNOG-mapper, orthology transfer)
| Orthologous group | 2DR0A |
|---|---|
| KEGG orthology |
K03071
|
| KEGG pathways |
map02024, map03060, map03070
|
| KEGG modules |
M00335
|
| Gene Ontology (6) |
GO:0005575, GO:0005618, GO:0005623, GO:0030312, GO:0044464, GO:0071944
|
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 | n/a |
|---|---|
| Polymorphic sites (≥ 0.1% of strains) | 0 synonymous, 3 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)
No Pfam-A domain above the gathering threshold (or not yet scanned).
Functional interaction network (STRING v12, guilt-by-association)
Closest characterised functional partner: higA (antitoxin HigA), high confidence from genomic context alone (score 1000 excluding text-mining).
| Partner | Product | Score | No text-mining | Channels (≥400) |
|---|---|---|---|---|
Rv1956 higA |
antitoxin HigA | 999 | 1000 ctx | neighborhood:882 coexpression:716 experimental:999 textmining:870 |
Rv1955 higB |
toxin HigB | 970 | 783 ctx | neighborhood:695 textmining:870 |
Rv1843c guaB1 |
inosine-5'-monophosphate dehydrogenase | 504 | 504 | experimental:484 |
Rv1077 cbs |
cystathionine beta-synthase | 501 | 501 | experimental:484 |
Rv1954A |
Rv1954A, len: 100 aa. Hypothetical unknown protein. | 661 | 429 ctx | neighborhood:429 textmining:431 |
Rv1246c relE |
toxin RelE | 524 | 54 | textmining:518 |
Rv1954c hyp |
hypothetical protein | 524 | 52 | textmining:519 |
Rv2021c higA2 |
transcriptional regulator | 536 | 51 | textmining:532 |
Rv2022c higB2 hyp |
hypothetical protein | 631 | 47 | textmining:629 |
Rv3182 higB3 hyp |
hypothetical protein | 591 | 44 | textmining:590 |
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: SecB-like chaperone
- MTBC0 PGAP product: SecB-like chaperone
- (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_216473.1)
- Domains: Pfam-A via hmmscan --cut_ga — none above threshold
- 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
2DR0A - Curated reference: UniProt P95257 (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 —
10 functional partner(s); context anchor
higA - Primary literature: none located yet; annotation rests on the domain/homology sources above.
Ancestral MTBC0 protein sequence
>mtbc0_002072|Rv1957| MTDRTDADDLDLQRVGARLAARAQIRDIRLLRTQAAVHRAPKPAQGLTYDLEFEPAVDADPATISAFVVRISCHLRIQNQAADDDVKEGDTKDETQDVATADFEFAALFDYHLQEGEDDPTEEELTAYAATTGRFALYPYIREYVYDLTGRLALPPLTLEILSRPMPVSPGAQWPATRGTP