Gene Ontology annotation through association of InterPro records with GO terms
Electronic Gene Ontology annotations created by transferring manual GO annotations between related proteins based on shared sequence features
Combined Automated Annotation using Multiple IEA Methods
UniProtKB entry A0A0H2MPV4 (A0A0H2MPV4_VARPD): PqqA peptide cyclase
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A0A0H2MPV4 (VPARA_00920, pqqE/moaA1) is a 383-residue PqqA peptide cyclase (EC 1.21.98.4, RHEA:56836; HAMAP MF_00660, InterPro IPR011843, NCBIfam TIGR02109, PANTHER PTHR11228:SF7) that catalyzes glutamate-tyrosine cross-linking in PqqA during PQQ biosynthesis.
"CC -!- FUNCTION: Catalyzes the cross-linking of a glutamate residue and a
CC tyrosine residue in the PqqA protein as part of the biosynthesis of
CC pyrroloquinoline quinone (PQQ). {ECO:0000256|HAMAP-Rule:MF_00660}."
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Binds a catalytic [4Fe-4S] cluster coordinated by three cysteines (Cys22, Cys26, Cys29) and an exchangeable S-adenosyl-L-methionine ligand.
"CC -!- COFACTOR:
CC Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883;
CC Evidence={ECO:0000256|HAMAP-Rule:MF_00660};
CC Note=Binds 1 [4Fe-4S] cluster. The cluster is coordinated with 3
CC cysteines and an exchangeable S-adenosyl-L-methionine.
CC {ECO:0000256|HAMAP-Rule:MF_00660};"
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Interacts with the peptide chaperone PqqD, which is required for PqqE catalytic activity.
"CC -!- SUBUNIT: Interacts with PqqD. The interaction is necessary for activity
CC of PqqE. {ECO:0000256|HAMAP-Rule:MF_00660}."
Pyrroloquinoline quinone biogenesis: demonstration that PqqE from Klebsiella pneumoniae is a radical S-adenosyl-L-methionine enzyme.
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Demonstrates that PqqE is a member of the radical SAM superfamily that binds [4Fe-4S] clusters and reductively cleaves S-adenosyl-L-methionine to 5'-deoxyadenosine and L-methionine.
"PqqE isolated anaerobically yields an active enzyme capable of cleaving SAM to methionine and 5'-deoxyadenosine in an uncoupled reaction"
Demonstration That the Radical S-Adenosylmethionine (SAM) Enzyme PqqE Catalyzes de Novo Carbon-Carbon Cross-linking within a Peptide Substrate PqqA in the Presence of the Peptide Chaperone PqqD.
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Demonstrates in vitro that PqqE, in complex with PqqD and a flavodoxin/flavodoxin reductase reducing system, catalyzes the SAM-dependent radical formation of a carbon-carbon bond between the glutamate and tyrosine side chains of PqqA.
"These results indicate that PqqE, in conjunction with PqqD, carries out the first step in PQQ biosynthesis: a radical-mediated formation of a new carbon-carbon bond between two amino acid side chains on PqqA."
Biogenesis of the peptide-derived redox cofactor pyrroloquinoline quinone.
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Reviews the mechanism of PqqE, including its N-terminal radical SAM [4Fe-4S] cluster (CxxxCxxC motif) and C-terminal SPASM-domain auxiliary iron-sulfur clusters (AuxI and AuxII).
"In the presence of reducing reagent and SAM, the [4Fe-4S] cluster in PqqE promotes the cleavage of SAM to 5’-deoxyadenosyl radical to initiate a series of steps culminating in a Glu-Tyr crosslink within PqqA."