mmaA1 Resolved · high auto-curated

H37Rv Rv0645c · MTBC0 mtbc0_000683 · 286 aa · 742880–743740 (-) · RefSeq NP_215159.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)mycolic acid methyltransferase MmaA1
MTBC0 PGAP re-annotationmycolic acid methyltransferase MmaA1
Revised (this work)Mycolic acid methyltransferase MmaA1. Pfam: CMAS (PF02353.27), Methyltransf_23 (PF13489.13), Methyltransf_25 (PF13649.13), Methyltransf_11 (PF08241.19).

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

Curated reference (UniProt)

UniProt P9WPB1 SwissProt · reviewed · Evidence at protein level
UniProt nameMycolic acid methyltransferase MmaA1
EC (curated) EC 2.1.1.-
Curated functionInvolved in the conversion of a cis-olefin into a trans-olefin with concomitant introduction of an allylic methyl branch at the proximal position of the precursor to both the methoxy and ketomycolic acids. It directly affects the cis- to trans ratio and indirectly affects the keto to methoxy ratio.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category M Cell wall / membrane / envelope biogenesis
Preferred namemmaA1
eggNOG descriptionsynthase
Orthologous groupCOG2230
EC number EC 2.1.1.79
KEGG orthology K00574
Gene Ontology (48) GO:0003674, GO:0003824, GO:0006082, GO:0006629, GO:0006631, GO:0006633, GO:0008150, GO:0008152, GO:0008168, GO:0008610, GO:0008757, GO:0008825 +36 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)

pN/pS 0.05 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 6 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
CMASPF02353.27 3.6e-1164–282 Mycolic acid cyclopropane synthetase
Methyltransf_23PF13489.13 6.2e-0953–223 Methyltransferase domain
Methyltransf_25PF13649.13 2.4e-0868–161 Methyltransferase domain
Methyltransf_11PF08241.19 6.8e-0568–164 Methyltransferase domain

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

Closest characterised functional partner: lipG (lipase/esterase LipG), medium confidence from genomic context alone (score 681 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0646c lipG lipase/esterase LipG 848 681 ctx neighborhood:675 textmining:543
Rv0647c hyp hypothetical protein 881 667 ctx neighborhood:664 textmining:658
Rv0449c hyp hypothetical protein 584 565 ctx fusion:466
Rv0644c mmaA2 cyclopropane mycolic acid synthase CmaA 530 509 ctx neighborhood:483
Rv0649 fabD2 malonyl CoA-acyl carrier protein transacylase 470 470 ctx neighborhood:470
Rv0650 sugar kinase 464 464 ctx neighborhood:463
Rv0648 alpha-mannosidase 447 446 ctx neighborhood:446
Rv3433c nnr bifunctional ADP-dependent (S)-NAD(P)H-hydrate dehydratase/NAD(P)H-hydrate epimerase 516 348
Rv3254 hyp hypothetical protein 424 61 textmining:412
Rv3787c S-adenosyl-L-methionine-dependent methyltransferase 547 44 textmining:546
Rv3305c amiA1 N-acyl-L-amino acid amidohydrolase AmiA 426 41 textmining:427

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: mycolic acid methyltransferase MmaA1
  • MTBC0 PGAP product: mycolic acid methyltransferase MmaA1
  • Pfam (hmmscan --cut_ga): CMAS PF02353.27 (E=4e-116), Methyltransf_23 PF13489.13 (E=6e-09), Methyltransf_25 PF13649.13 (E=2e-08), Methyltransf_11 PF08241.19 (E=7e-05)
  • (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_215159.1)
  • Domains: Pfam-A via hmmscan --cut_ga — CMAS (PF02353.27), Methyltransf_23 (PF13489.13), Methyltransf_25 (PF13649.13), Methyltransf_11 (PF08241.19)
  • 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 COG2230
  • Curated reference: UniProt P9WPB1 (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 — 11 functional partner(s); context anchor lipG
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_000683|Rv0645c|mmaA1
MAKLRPYYEESQSAYDISDDFFALFLDPTWVYTCAYFERDDMTLEEAQLAKVDLALDKLNLEPGMTLLDVGCGWGGALVRAVEKYDVNVIGLTLSRNHYERSKDRLAAIGTQRRAEARLQGWEEFEENVDRIVSFEAFDAFKKERYLTFFERSYDILPDDGRMLLHSLFTYDRRWLHEQGIALTMSDLRFLKFLRESIFPGGELPSEPDIVDNAQAAGFTIEHVQLLQQHYARTLDAWAANLQAARERAIAVQSEEVYNNFMHYLTGCAERFRRGLINVAQFTMTK