mptA Resolved · high auto-curated
H37Rv Rv2174 · MTBC0 mtbc0_002308 ·
516 aa · 2461916–2463466 (+) ·
RefSeq NP_216690.1
Annotation: from legacy to revised
| Legacy (H37Rv / Mycobrowser) | alpha(1->6)-mannopyranosyltransferase A |
|---|---|
| MTBC0 PGAP re-annotation | alpha-(1->6)-mannopyranosyltransferase A |
| Revised (this work) | Alpha-(1->6)-mannopyranosyltransferase A. Pfam: MptA_B_family (PF26314.1), MptA_C (PF27552.1). |
Auto-curated: this verdict and function were generated by rules from PGAP + Pfam + Foldseek and have not been hand-reviewed.
Curated reference (UniProt)
| UniProt |
O53508
SwissProt · reviewed
· Evidence at protein level
|
|---|---|
| UniProt name | Alpha-(1->6)-mannopyranosyltransferase A |
| EC (curated) |
EC 2.4.1.-
|
| Curated function | Involved in the latter stages of the biosynthesis of the alpha-(1->6) mannan core of lipomannan (LM). Catalyzes the addition of alpha-(1->6)-mannose residue. |
Functional vocabulary (eggNOG-mapper, orthology transfer)
| COG category |
S Function unknown
|
|---|---|
| Preferred name | mptA |
| eggNOG description | Carotene biosynthesis associated membrane protein |
| Orthologous group | 2DBIT |
| KEGG orthology |
K14337, K14339
|
| Gene Ontology (28) |
GO:0000030, GO:0003674, GO:0003824, GO:0006629, GO:0006643, GO:0006664, GO:0008150, GO:0008152, GO:0008610, GO:0009058, GO:0009247, GO:0009987 +16 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 | 0.578 · relaxed/neutral |
|---|---|
| Polymorphic sites (≥ 0.1% of strains) | 4 synonymous, 6 missense, 0 nonsense, 1 frameshift |
| Disruption | 1 distinct premature-stop/frameshift site(s); most common in 1.13% of strains (1643) · 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)
| Pfam | Accession | i-Evalue | Residues | Description |
|---|---|---|---|---|
MptA_B_family | PF26314.1 | 1.6e-91 | 39–304 | Alpha-(1->6)-mannopyranosyltransferase family |
MptA_C | PF27552.1 | 1.5e-19 | 453–491 | MptA C-terminal domain |
Functional interaction network (STRING v12, guilt-by-association)
Closest characterised functional partner: idsA2 (geranylgeranyl pyrophosphate synthetase IdsA), high confidence from genomic context alone (score 911 excluding text-mining).
| Partner | Product | Score | No text-mining | Channels (≥400) |
|---|---|---|---|---|
Rv1459c mptB |
alpha-(1->6)-mannopyranosyltransferase | 948 | 928 | database:900 |
Rv2173 idsA2 |
geranylgeranyl pyrophosphate synthetase IdsA | 949 | 911 ctx | neighborhood:882 textmining:455 |
Rv0365c hyp |
hypothetical protein | 720 | 721 ctx | cooccurence:719 |
Rv0556 |
transmembrane protein | 687 | 687 ctx | cooccurence:680 |
Rv1632c hyp |
hypothetical protein | 633 | 633 ctx | cooccurence:630 |
Rv3850 hyp |
hypothetical protein | 625 | 625 ctx | cooccurence:625 |
Rv2418c octT hyp |
hypothetical protein | 624 | 625 ctx | cooccurence:612 |
Rv3438 hyp |
hypothetical protein | 616 | 616 ctx | cooccurence:613 |
Rv2186c hyp |
hypothetical protein | 614 | 614 ctx | cooccurence:614 |
Rv2695 hyp |
hypothetical protein | 591 | 591 ctx | cooccurence:539 |
Rv3256c hyp |
hypothetical protein | 601 | 590 ctx | cooccurence:565 |
Rv3415c hyp |
hypothetical protein | 566 | 566 ctx | cooccurence:565 |
Rv2049c hyp |
hypothetical protein | 564 | 564 ctx | cooccurence:563 |
Rv1166 lpqW |
monoacyl phosphatidylinositol tetramannoside-binding protein LpqW | 651 | 562 ctx | cooccurence:557 |
Rv2732c |
transmembrane protein | 559 | 560 ctx | cooccurence:557 |
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: alpha(1->6)-mannopyranosyltransferase A
- MTBC0 PGAP product: alpha-(1->6)-mannopyranosyltransferase A
- Pfam (hmmscan --cut_ga): MptA_B_family PF26314.1 (E=2e-91), MptA_C PF27552.1 (E=1e-19)
- (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_216690.1)
- Domains: Pfam-A via hmmscan --cut_ga — MptA_B_family (PF26314.1), MptA_C (PF27552.1)
- 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
2DBIT - Curated reference: UniProt O53508 (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 —
68 functional partner(s); context anchor
idsA2 - Primary literature: none located yet; annotation rests on the domain/homology sources above.
Ancestral MTBC0 protein sequence
>mtbc0_002308|Rv2174|mptA MTTPSHAPAVDLATAKDAVVQHLSRLFEFTTGPQGGPARLGFAGAVLITAGGLGAGSVRQHDPLLESIHMSWLRFGHGLVLSSILLWTGVGVMLLAWLGLGRRVLAGEATEFTMRATTVIWLAPLLLSVPVFSRDTYSYLAQGALLRDGLDPYAVGPVGNPNALLDDVSPIWTITTAPYGPAFILVAKFVTVIVGNNVVAGTMLLRLCMLPGLALLVWATPRLASHLGTHGPTALWICVLNPLVLIHLMGGVHNEMLMVGLMTAGIALTVQGRNVAGIILITVAIAVKATAGIALPFLVWVWLRHLRERRGYRPVQAFLAAAAISLLIFVAVFAVLSAVAGVGLGWLTALAGSVKIINWLTVPTGAANVIHALGRGLFTVDFYTLLRITRLIGIVIIAVSLPLLWWRFRRDDRAALTGVAWSMLIVVLFVPAALPWYYSWPLAVAAPLAQSRRAIAAIAGLSTWVMVIFKPDGSHGMYSWLHFWIATACALTAWYVLYRSPDRRGVQAATPVVNTP