malQ Resolved · high auto-curated

H37Rv Rv1781c · MTBC0 mtbc0_001895 · 724 aa · 2033313–2035487 (-) · RefSeq NP_216297.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)4-alpha-glucanotransferase
MTBC0 PGAP re-annotation4-alpha-glucanotransferase
Revised (this work)4-alpha-glucanotransferase. Pfam: MalQ_N (PF21226.5), Glyco_hydro_77 (PF02446.24).

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

Curated reference (UniProt)

UniProt P9WK23 SwissProt · reviewed · Evidence at protein level
UniProt name4-alpha-glucanotransferase
EC (curated) EC 2.4.1.25

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category G Carbohydrate transport and metabolism
Preferred namemalQ
eggNOG description4-alpha-glucanotransferase
Orthologous groupCOG1640
EC number EC 2.4.1.25
KEGG orthology K00705
KEGG pathways map00500, map01100
CAZy family GH77
Gene Ontology (8) GO:0005575, GO:0005622, GO:0005623, GO:0005737, GO:0005829, GO:0044424, GO:0044444, GO:0044464

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 0.506 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 7 synonymous, 9 missense, 1 nonsense, 0 frameshift
Disruption 1 distinct premature-stop/frameshift site(s); most common in 0.65% of strains (951) · 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
MalQ_NPF21226.5 1.8e-2768–160 MalQ N-terminal beta sandwich domain
Glyco_hydro_77PF02446.24 3.4e-127179–687 4-alpha-glucanotransferase

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

Closest characterised functional partner: treX (maltooligosyl trehalose synthase), high confidence from genomic context alone (score 997 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1564c treX maltooligosyl trehalose synthase 998 997 ctx fusion:900 cooccurence:557 coexpression:412 database:900 textmining:622
Rv1326c glgB 1,4-alpha-glucan branching protein 997 991 ctx fusion:736 cooccurence:441 coexpression:409 database:900 textmining:773
Rv1563c treY maltooligosyl trehalose synthase 982 969 ctx fusion:899 cooccurence:438 coexpression:423 textmining:458
Rv1328 glgP glycogen phosphorylase 984 966 coexpression:648 database:900 textmining:548
Rv1327c glgE alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase 980 951 database:900 textmining:610
Rv0127 mak maltokinase 973 947 database:900 textmining:517
Rv0126 treS trehalose synthase/amylase TreS 969 939 database:900 textmining:514
Rv1213 glgC glucose-1-phosphate adenylyltransferase 993 938 database:900 textmining:893
Rv3068c pgmA phosphoglucomutase PgmA 943 924 database:900
Rv2471 aglA alpha-glucosidase AglA 954 922 database:900 textmining:439
Rv1212c glgA capsular glucan synthase 968 914 database:900 textmining:649
Rv3032 glycogen synthase 965 900 database:900 textmining:664
Rv3031 1,4-alpha-glucan-branching protein 943 900 database:900 textmining:456
Rv0993 galU UTP--glucose-1-phosphate uridylyltransferase 912 900 database:900
Rv1562c treZ malto-oligosyltrehalose trehalohydrolase 855 772 ctx cooccurence:578 coexpression:411

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: 4-alpha-glucanotransferase
  • MTBC0 PGAP product: 4-alpha-glucanotransferase
  • Pfam (hmmscan --cut_ga): MalQ_N PF21226.5 (E=2e-27), Glyco_hydro_77 PF02446.24 (E=3e-127)
  • (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_216297.1)
  • Domains: Pfam-A via hmmscan --cut_ga — MalQ_N (PF21226.5), Glyco_hydro_77 (PF02446.24)
  • 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 COG1640
  • Curated reference: UniProt P9WK23 (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 — 28 functional partner(s); context anchor treX
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_001895|Rv1781c|malQ
MTELAPSLVELARRFGIATEYTDWTGRQVLVSEATLVAALAALGVPAQTEQQRNDALAAQLRSYWARPLPATIVMRAGEQTQFRVHVTDGAPADVWLQLEDGTTRAEVVQVDNFTPPFDLDGRWIGEASFVLPADLPLGYHRVNLRSGDSQASAAVVVTPDWLGLPDKLAGRRAWGLAVQLYSVRSRQSWGIGDLTDLANLALWSASAHGAGYVLVNPLHAATLPGPAGRSKPIEPSPYLPTSRRFVNPLYLRVEAIPELVDLPKRGRVQRLRTNVQQHADQLDTIDRDSAWAAKRAALKLVHRVPRSAGRELAYAAFRTREGRALDDFATWCALAETYGDDWHRWPKSLRHPDASGVADFVDKHADAVDFHRWLQWQLDEQLASAQSQALRAGMSLGIMADLAVGVHPNGADAWALQDVLAQGVTAGAPPDEFNQLGQDWSQPPWRPDRLAEQEYRPFRALIQAALRHAGAVRIDHIIGLFRLWWIPDGAPPTQGTYVRYDHDAMIGIVALEAHRAGAVVVGEDLGTVEPWVRDYLLLRGLLGTSILWFEQDRDCGPAGTPLPAERWREYCLSSVTTHDLPPTAGYLAGDQVRLRESLGLLTNPVEAELESARADRAAWMAELRRVGLLADGAEPDSEEAVLALYRYLGRTPSRLLAVALTDAVGDRRTQNQPGTTDEYPNWRVPLTGPDGQPMLLEDIFTDRRAATLAEAVRAATTSPMSCW