mazF3 Resolved · high auto-curated

H37Rv Rv1102c · MTBC0 mtbc0_001185 · 103 aa · 1239100–1239411 (-) · RefSeq NP_215618.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)mRNA interferase MazF3
MTBC0 PGAP re-annotationtype II toxin-antitoxin system toxin endoribonuclease MazF3
Revised (this work)Type II toxin-antitoxin system toxin endoribonuclease MazF3. Pfam: PemK_toxin (PF02452.24).

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

Curated reference (UniProt)

UniProt P9WIH9 SwissProt · reviewed · Evidence at protein level
UniProt nameEndoribonuclease MazF3
EC (curated) EC 3.1.-.-
Curated functionToxic component of a type II toxin-antitoxin (TA) system. Acts as an mRNA and 23S rRNA interferase, cleaving predominantly after the first 2 Us in the sequence 5'-UUCCU-3'; in 23S rRNA only cleaves once in the ribosomal A site in dissociated but not intact ribosomes. Cleavage of 23S rRNA inhibits protein translation; the 23S rRNA region cleaved is involved in tRNA-binding in the A site, 30S and 50S subunit interaction and ribosome recycling factor association. Upon expression in E.coli and M.smegmatis inhibits cell growth and colony formation. It dramatically increases persister cell formation.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category T Signal transduction mechanisms
Preferred namemazF3
eggNOG descriptionPemK-like, MazF-like toxin of type II toxin-antitoxin system
Orthologous groupCOG2337
KEGG orthology K07171
Gene Ontology (92) GO:0003674, GO:0003824, GO:0004518, GO:0004519, GO:0004521, GO:0004540, GO:0006139, GO:0006355, GO:0006401, GO:0006402, GO:0006417, GO:0006725 +80 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 n/a
Polymorphic sites (≥ 0.1% of strains) 0 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)

PfamAccessioni-EvalueResiduesDescription
PemK_toxinPF02452.24 2.6e-1110–92 PemK-like, MazF-like toxin of type II toxin-antitoxin system

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

Closest characterised functional partner: mazE3 (antitoxin MazE3), high confidence from genomic context alone (score 916 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1103c mazE3 antitoxin MazE3 960 916 ctx neighborhood:882 textmining:546
Rv1104 Rv1104, (MTV017.57), len: 229 aa. Possible para-nitrobenzyl esterase (fragment; possibly first part). Similar to the N-terminal domain of ma 622 622 ctx neighborhood:620
Rv1991A mazE6 antitoxin MazE6 782 607 experimental:434 textmining:468
Rv1942c mazF5 toxin MazF5 851 589 ctx cooccurence:586 textmining:652
Rv2801A mazE9 antitoxin MazE9 568 563
Rv3407 vapB47 antitoxin VapB47 548 549 ctx cooccurence:543
Rv1101c hyp hypothetical protein 535 535 ctx neighborhood:528
Rv1725c hyp hypothetical protein 503 503 coexpression:420
Rv3408 vapC47 ribonuclease VapC47 639 488 ctx cooccurence:472
Rv3384c vapC46 ribonuclease VapC46 522 444 ctx cooccurence:438
Rv1962c vapC35 ribonuclease VapC35 436 435 ctx cooccurence:430
Rv0456A mazF1 toxin MazF1 589 419 ctx cooccurence:418
Rv3095 HTH-type transcriptional regulator 416 417 coexpression:417
Rv0659c mazF2 toxin MazF2 648 407 ctx cooccurence:402 textmining:431
Rv2472 hyp hypothetical protein 414 406

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: mRNA interferase MazF3
  • MTBC0 PGAP product: type II toxin-antitoxin system toxin endoribonuclease MazF3
  • Pfam (hmmscan --cut_ga): PemK_toxin PF02452.24 (E=3e-11)
  • (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_215618.1)
  • Domains: Pfam-A via hmmscan --cut_ga — PemK_toxin (PF02452.24)
  • 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 COG2337
  • Curated reference: UniProt P9WIH9 (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 mazE3
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_001185|Rv1102c|mazF3
MRPIHIAQLDKARPVLILTREVVRPHLTNVTVAPITTTVRGLATEVPVDAVNGLNQPSVVSCDNIQTIPVCDLGRQIGYLLASQEPALAEAIGNAFDLDWVVA