Rv1987 Family assigned · medium auto-curated
H37Rv Rv1987 · MTBC0 mtbc0_002111 ·
142 aa · 2254639–2255067 (+) ·
RefSeq NP_216503.1
Annotation: from legacy to revised
| Legacy (H37Rv / Mycobrowser) | chitinase |
|---|---|
| MTBC0 PGAP re-annotation | cellulose-binding protein |
| Revised (this work) | Cellulose-binding protein. Pfam: CBM_2 (PF00553.26). |
Auto-curated: this verdict and function were generated by rules from PGAP + Pfam + Foldseek and have not been hand-reviewed.
Curated reference (UniProt)
| UniProt |
P9WLQ1
SwissProt · reviewed
· Evidence at protein level
|
|---|---|
| UniProt name | Cellulose/chitin binding protein Rv1987 |
| Curated function | Carbohydrate binding protein that binds chitin and cellulose. Lacks enzymatic activity and does not hydrolyze chitin and cellulose. May interact with mycobacterial biofilms, which are rich in cellulose, and play a role in biofilm formation. Could also act as an adhesin, improving the initial attachment to host cells and aiding M.tuberculosis during the initial stages of infection. Recombinant M.smegmatis harboring Rv1987 shows enhanced cytoadhesion to human lung epithelial cell line A549..; FUNCTION: When expressed in M.smegmatis as a model mycobacterium, Rv1987 acts as a virulence factor that. |
Functional vocabulary (eggNOG-mapper, orthology transfer)
| COG category |
G Carbohydrate transport and metabolism
|
|---|---|
| eggNOG description | CBD_II |
| Orthologous group | COG3469 |
| Gene Ontology (6) |
GO:0001871, GO:0003674, GO:0005488, GO:0030246, GO:0030247, GO:0030248
|
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 | 0.24 · purifying |
|---|---|
| Polymorphic sites (≥ 0.1% of strains) | 3 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)
| Pfam | Accession | i-Evalue | Residues | Description |
|---|---|---|---|---|
CBM_2 | PF00553.26 | 1.2e-34 | 41–139 | Cellulose binding domain |
Functional interaction network (STRING v12, guilt-by-association)
Closest characterised functional partner: pirG (cell surface protein), medium confidence from genomic context alone (score 659 excluding text-mining).
| Partner | Product | Score | No text-mining | Channels (≥400) |
|---|---|---|---|---|
Rv3810 pirG |
cell surface protein | 658 | 659 ctx | cooccurence:573 |
Rv3414c sigD |
ECF RNA polymerase sigma factor SigD | 651 | 652 | coexpression:651 |
Rv0315 |
beta-1,3-glucanase | 662 | 617 ctx | cooccurence:602 |
Rv0518 hyp |
hypothetical protein | 630 | 607 | experimental:405 |
Rv1836c hyp |
hypothetical protein | 598 | 599 ctx | cooccurence:593 |
Rv0290 eccD3 |
ESX-3 secretion system protein EccD | 585 | 586 ctx | cooccurence:584 |
Rv2743c hyp |
hypothetical protein | 529 | 529 ctx | cooccurence:529 |
Rv1084 hyp |
hypothetical protein | 537 | 518 | experimental:465 |
Rv0941c hyp |
hypothetical protein | 498 | 498 ctx | cooccurence:498 |
Rv0179c lprO |
lipoprotein LprO | 493 | 494 | coexpression:494 |
Rv0412c glnX |
membrane protein | 478 | 478 ctx | cooccurence:473 |
Rv2145c wag31 |
cell wall synthesis protein Wag31 | 474 | 474 | coexpression:474 |
Rv1075c hyp |
hypothetical protein | 493 | 461 | experimental:405 |
Rv3593 lpqF |
lipoprotein LpqF | 458 | 458 ctx | cooccurence:450 |
Rv0681 |
transcriptional regulator | 453 | 453 ctx | cooccurence:453 |
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: chitinase
- MTBC0 PGAP product: cellulose-binding protein
- Pfam (hmmscan --cut_ga): CBM_2 PF00553.26 (E=1e-34)
- (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_216503.1)
- Domains: Pfam-A via hmmscan --cut_ga — CBM_2 (PF00553.26)
- 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
COG3469 - Curated reference: UniProt P9WLQ1 (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 —
35 functional partner(s); context anchor
pirG - Primary literature: none located yet; annotation rests on the domain/homology sources above.
Ancestral MTBC0 protein sequence
>mtbc0_002111|Rv1987| MAGLNIYVRRWRTALHATVSALIVAILGLAITPVASAATARATLSVTSTWQTGFIARFTITNSSTAPLTDWKLEFDLPAGESVLHTWNSTVARSGTHYVLSPANWNRIIAPGGSATGGLRGGLTGSYSPPSSCLLNGQYPCT