aroQ (P9WPX7, Mycobacterium tuberculosis H37Rv, Rv2537c) review notes

Provenance of this notes file

Provider deep research was unavailable for this review (no deep-research provider key in
the session), so no aroQ-deep-research-*.md file exists. These notes were compiled by the
reviewer from the cached publications in publications/ (PMID:12387860 and PMID:1910148
were fetched for this review), the UniProt record (aroQ-uniprot.txt), the cached
Reactome reaction R-MTU-964851, the PTHR21272 family review
(interpro/panther/PTHR21272/PTHR21272-review.yaml, for which AroQ is the reference
protein) and one UniProt REST query recorded below.

Family: PANTHER PTHR21272 (CATABOLIC 3-DEHYDROQUINASE), subfamily PTHR21272:SF3, under the
PAINT root node PTN000479790; InterPro IPR001874/IPR018509/IPR036441, Pfam PF01220,
NCBIfam TIGR01088, HAMAP MF_00169, PROSITE PS01029. No PAINT IRD/IKR loss on the AroQ
lineage (just paint-losses MYCTU aroQ).

Gene and evolutionary origin

• Cloned with aroB; unrelated to the E. coli-type (type I) biosynthetic DHQase but similar
  to the fungal catabolic DHQases.
  PMID:1910148
  PMID:1910148
• Reviewer check (UniProt REST, 2026-11-11): query=ec:4.2.1.10 AND organism_id:83332
  returned only P9WPX7 (aroQ, Rv2537c), so AroQ is the only annotated 3-dehydroquinase of
  M. tuberculosis H37Rv and must supply the shikimate-pathway step.

Activity and structure

• Type II 3-dehydroquinase (EC 4.2.1.10), 3-dehydroquinate = 3-dehydroshikimate + H2O.
  Purified recombinant enzyme:
  PMID:1329726
  PMID:1329726
  The gene also supported quinate growth when expressed in a fungal qutE mutant:
  PMID:1329726
  This shows catalytic capacity in a heterologous catabolic pathway, not a catabolic role
  in M. tuberculosis.
• Mechanism: PMID:10360352
  Gourley et al. solved the M. tuberculosis type II structure (PDB 2DHQ in the UniProt
  record) together with a type I enzyme:
  PMID:10360352
• Active site (UniProt FT, structure-based): Tyr-25 proton acceptor, His-102 proton donor,
  Arg-20 transition-state stabilizer; many inhibitor complexes (PDB 1H05, 2Y71, 4KI7 ...).
• Substrate recognition by polyanions: PMID:12387860
• Quaternary structure: homododecamer (UniProt SUBUNIT, from PMID:10360352, PMID:12387860).

Pathway role

• Reactome R-MTU-964851: [Reactome:R-MTU-964851 "Unlike fungi DHQ dehydratases, AroQ doesn't take part in catabolism reactions (Moore et al, 1992)."]
• UniProt PATHWAY: chorismate biosynthesis, step 3/7. AroQ is thus the biosynthetic
  DHQase of M. tuberculosis. The PTHR21272 family review judges the PAINT quinate
  catabolism IBD at the family root (PTN000479790) TOO_DEEP: it is seeded only by A. nidulans
  QutE and passes the catabolic process to the bacterial biosynthetic AroQ enzymes.

Localization

• Soluble cytosolic enzyme (no signal peptide or transmembrane segment; small 147-residue
  dodecamer). Reactome places the reaction in the cytosol.