pks4 Resolved · high auto-curated

H37Rv Rv1181 · MTBC0 - · 1582 aa · 1315234–1319982 (+) · RefSeq NP_215697.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)polyketide beta-ketoacyl synthase
MTBC0 PGAP re-annotation
Revised (this work)Polyketide beta-ketoacyl synthase. Pfam: Acyl_transf_1 (PF00698.27), PKS_DH_N (PF21089.4), PS-DH (PF14765.13), SpnB_Rossmann (PF22953.4), ADH_N (PF08240.18), ADH_zinc_N (PF00107.33), ADH_zinc_N_2 (PF13602.13), KR (PF08659.17), adh_short (PF00106.32), PP-binding (PF00550.32).

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

Annotated on the H37Rv protein: this gene has no 1:1 ancestral MTBC0 anchor (PE/PPE, paralogue, IS element, or otherwise unanchored CDS).

Curated reference (UniProt)

UniProt A0A089QRB9 SwissProt · reviewed · Evidence at protein level
UniProt nameMycolipanoate synthase
EC (curated) EC 2.3.1.252
Curated functionPolyketide synthase involved in the biosynthesis of methyl-branched fatty acids such as mycolipanoic, mycolipenic (phthienoic) and mycolipodienoic acids required for the synthesis of a major class of polyacylated trehaloses. Catalyzes the elongation of CoA esters of long-chain fatty acids by incorporation of three methylmalonyl (but not malonyl) residues, to form trimethyl-branched fatty-acids.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category Q Secondary metabolites biosynthesis, transport and catabolism
Preferred namepks2
eggNOG descriptionpolyketide synthase
Orthologous groupCOG0604
EC number EC 2.3.1.111, EC 2.3.1.252
KEGG orthology K11628, K12431, K12432, K12433, K12442, K12443
Gene Ontology (101) GO:0005575, GO:0005618, GO:0005622, GO:0005623, GO:0005737, GO:0005829, GO:0005886, GO:0006066, GO:0006082, GO:0006629, GO:0006631, GO:0006633 +89 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 0.41 · purifying
Polymorphic sites (≥ 0.1% of strains) 14 synonymous, 16 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
Acyl_transf_1PF00698.27 5.7e-9835–351 Acyl transferase domain
PKS_DH_NPF21089.4 2.5e-21395–493 Polyketide synthase dehydratase domain
PS-DHPF14765.13 6.4e-24521–673 Polyketide synthase dehydratase N-terminal domain
SpnB_RossmannPF22953.4 3.6e-11733–876 Polyketide synthase extender module SpnB, Rossmann fold domain
ADH_NPF08240.18 6.3e-10922–1003 Alcohol dehydrogenase GroES-like domain
ADH_zinc_NPF00107.33 1.0e-211047–1157 Zinc-binding dehydrogenase
ADH_zinc_N_2PF13602.13 3.0e-201079–1218 Zinc-binding dehydrogenase
KRPF08659.17 4.3e-601242–1420 KR domain
adh_shortPF00106.32 9.0e-091245–1400 short chain dehydrogenase
PP-bindingPF00550.32 6.5e-091507–1570 Phosphopantetheine attachment site

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

Closest characterised functional partner: fas (fatty acid synthase), high confidence from genomic context alone (score 1000 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2524c fas fatty acid synthase 999 1000 ctx neighborhood:544 coexpression:812 experimental:999 database:549 textmining:736
Rv1180 pks3 polyketide beta-ketoacyl synthase 999 1000 ctx neighborhood:646 fusion:806 cooccurence:756 coexpression:862 database:900
Rv1182 papA3 acyltransferase papA3 997 989 ctx neighborhood:648 coexpression:917 experimental:473 textmining:786
Rv2933 ppsC phthiocerol synthesis polyketide synthase type I PpsC 990 983 ctx neighborhood:544 experimental:795 database:720 textmining:445
Rv3825c pks2 phthioceranic/hydroxyphthioceranic acid synthase 988 980 ctx neighborhood:544 coexpression:798 experimental:795 textmining:451
Rv2383c mbtB phenyloxazoline synthase 993 978 ctx neighborhood:544 coexpression:876 experimental:473 textmining:707
Rv2947c pks15 polyketide synthase 982 964 ctx fusion:829 cooccurence:749 textmining:532
Rv2243 fabD malonyl CoA-acyl carrier protein transacylase 971 963 coexpression:601 experimental:787 database:549
Rv0101 nrp peptide synthetase Nrp 968 947 coexpression:767 experimental:473 textmining:424
Rv2048c pks12 polyketide synthase 969 945 ctx neighborhood:544 experimental:795 textmining:471
Rv2382c mbtC polyketide synthetase 937 930 ctx fusion:681 cooccurence:742
Rv2940c mas multifunctional mycocerosic acid synthase 958 929 ctx neighborhood:544 experimental:795 textmining:443
Rv1527c pks5 polyketide synthase 958 928 ctx neighborhood:544 experimental:795 textmining:439
Rv2932 ppsB phthiocerol synthesis polyketide synthase type I PpsB 940 915 ctx neighborhood:481 database:720
Rv3800c pks13 polyketide synthase 957 903 ctx neighborhood:544 coexpression:676 textmining:582

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

  • Annotation from H37Rv (no MTBC0 1:1 anchor; H37Rv protein used): polyketide beta-ketoacyl synthase
  • Pfam (hmmscan --cut_ga): Acyl_transf_1 PF00698.27 (E=6e-98), PKS_DH_N PF21089.4 (E=2e-21), PS-DH PF14765.13 (E=6e-24), SpnB_Rossmann PF22953.4 (E=4e-11), ADH_N PF08240.18 (E=6e-10), ADH_zinc_N PF00107.33 (E=1e-21), ADH_zinc_N_2 PF13602.13 (E=3e-20), KR PF08659.17 (E=4e-60), adh_short PF00106.32 (E=9e-09), PP-binding PF00550.32 (E=7e-09)
  • (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_215697.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Acyl_transf_1 (PF00698.27), PKS_DH_N (PF21089.4), PS-DH (PF14765.13), SpnB_Rossmann (PF22953.4), ADH_N (PF08240.18), ADH_zinc_N (PF00107.33), ADH_zinc_N_2 (PF13602.13), KR (PF08659.17), adh_short (PF00106.32), PP-binding (PF00550.32)
  • 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 COG0604
  • Curated reference: UniProt A0A089QRB9 (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 — 455 functional partner(s); context anchor fas
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv1181|pks4
MTASSFDELSAALRDVAGDQIPYQPAVGHDDRGPVWVFSGQGSQWPGMGTELLVAEPVFAATVAAMEPVIARESGFSVTEAMSAPQTVSGIDRVQPTIFAVQVALAAALKSYGVRPGAIIGHSLGEAAAAVVAGALSLHDGLRVICRRSRLMSRIAGSGAMASVELPGQQVLSELAIRGISDVVLSVVASPTSTVVGGATQSIRDLVAAWEQQDVLAREVAVDVASHTPQVDPILDELLEVLAEVDPTAPEIPYYSATLWDPRERPSFTGEYWVENLRYTVRFAAAVQAALKDGYRVFGELAPHPLLTYAVEQNAASLDMPIATLAAMRRGEQLPFGLRGFVADVHNAGAKVDFSVQYPDGRLVDAPLPSWTHRTLMLSREDSHRSHTGAVQAVHPLLGAHVHLLEEPERHVWQAGVGTGAHPWLGDHRIHNVAAFPGAAYCEMALAAARTTLGELSEVRDIKFEQTLLLDEQTVVSSAATIAAPGILQFAVESHQEGEPARRASAMLHALEEMPQPPGYDTNALTAAHESSMSGEELRKMFNSLGIQYGPAFSGLVAVHTARGDVTTVLAEVALPGAIRSQQSAYASHPALLDACFQSVLVHPEVQKATVGGLMLPVGVRRLRNYHSTRSAHYCLARVTSSSRAGECEADLDVFDQAGTVLLTVEGLRLAAGISEHERANRVFDERLLTIEWERGELPEVPQIDAGSWLLLSASEADPLTAQLADALNAVGAQSTSVASASDVAQLRSLLGGRLTGVVVVTGPPTGGLTQCGRDYVSQLVGIARELAELPGEPPRLFVVTRSAASVLPSDLANLEQAGLRGLMRVIDSEHPHLGATAIDVDNDETVAALVASQLQSGSQEDETAWRNGIWYTARLRPGPLRPAERRTAVVEYRRDGMRLQIRTPGDLESLEFVTFDRVAPGPGEIEVAVTASSVNFADVLVAFGRYPTFEGYRQQLGIDFAGVVTAVGPDVTEHRIGDHVGGMSANGCWSTFVRCDARLAVTLPPELPVAAAAAVPTASATAWYALHDLARICSDDKVLIHSGTGGVGQAAIAIARAAGCEIFATAGSAQRRQLLHDMGVEHVYDSRSTEFAEQIRGDTDGYGVDVVLNSLPGAAQRAGIELLAFGGRFVEIGKRDIYGDTRLGLFPFRRNLSLYAVDLALLTHSHPHTVRRLLKTVYQHTVEGTLPVPQTTHYPIHDAAVAIRLVGGAGHTGKVVLDVPRTGEGVAVVPPEQVRTSRPDGAYLVTGGLGGLGLFLAGELAAAGCGRIVLNSRSTPSPHATRVIERLRAAGADIQVECGDIADAATAHRVVAVATASGLPVRGVLHAAAVVEDATLANVTDELIDRCWAPKVHGAWNIHRATAAQPLEWFCLFSSAAALVGSPGQGAYAAANSWLDAFAHWRRAQGLPATSIAWGAWAEIGRATALAEGTGAAIAPAEGARAFQTLLRYGRAYSGYAPIMGTPWLTAFAQRSRFAEAFHATGQNQPATGKFLAELGSLPREEWPRTVRRLVSDQISLLLRRTIDPDRPLSDYGLDSLGNLELRTRIETETGIRVSPTKITTVRGLAEHVCDELAAAQSAPV