UniProt functional annotation for H2E7Q8



	UniProt functional annotation for H2E7Q8

UniProt code: H2E7Q8.

Organism: Galerina marginata (strain CBS 339.88).

Taxonomy: Eukaryota; Fungi; Dikarya; Basidiomycota; Agaricomycotina; Agaricomycetes; Agaricomycetidae; Agaricales; Strophariaceae; Galerina.

Function: Dual function macrocyclase-peptidase involved in the biosynthesis of the highly toxic amanitin toxin family of macrocycles (PubMed:22202811, PubMed:28866879, PubMed:29051530). Cleaves peptide bonds on the C-terminal side of prolyl residues (PubMed:29051530). The enzyme first removes 10 residues from the N-terminus of a 35-residue substrate (PubMed:29051530). Conformational trapping of the 25 amino- acid peptide forces the enzyme to release this intermediate rather than proceed to macrocyclization (PubMed:29051530). The enzyme rebinds the 25 amino-acid peptide in a different conformation and catalyzes macrocyclization of the N-terminal eight residues (PubMed:28866879, PubMed:29051530). {ECO:0000269|PubMed:22202811, ECO:0000269|PubMed:28866879, ECO:0000269|PubMed:29051530}.

Catalytic activity: Reaction=Hydrolysis of Pro-|-Xaa >> Ala-|-Xaa in oligopeptides.; EC=3.4.21.26; Evidence={ECO:0000269|PubMed:28866879, ECO:0000269|PubMed:29051530};

Biophysicochemical properties: Kinetic parameters: KM=23 uM for the full alpha-amanitin 35mer proprotein {ECO:0000269|PubMed:29051530}; KM=51 uM for the 25mer IWGIGCNPWTAEHVDQTLASGNDIC {ECO:0000269|PubMed:29051530}; KM=19 uM for the 25mer LWGIGCNPWTAEHVDQTLASGNDIC {ECO:0000269|PubMed:29051530}; KM=8 uM for the 25mer IFGIGCNPWTAEHVDQTLASGNDIC {ECO:0000269|PubMed:29051530}; KM=28 uM for the 25mer IWGIGSNPWTAEHVDQTLASGNDIC {ECO:0000269|PubMed:29051530}; KM=10 uM for the 25mer IWGIGCNPWTAEHVDQTLASGNDIS {ECO:0000269|PubMed:29051530}; KM=25 uM for the 19mer IWGIGCNPDQTLASGNDIC {ECO:0000269|PubMed:29051530}; KM=380 uM for the 14mer IWGIGCNPWTAEHV {ECO:0000269|PubMed:29051530}; KM=24.4 uM for the 13mer IWGIGCNPWTAEH {ECO:0000269|PubMed:29051530};

Subunit: Monomer. {ECO:0000250|UniProtKB:P48147}.

Similarity: Belongs to the peptidase S9A family. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.


Organism:		Galerina marginata (strain CBS 339.88).
Taxonomy:		Eukaryota; Fungi; Dikarya; Basidiomycota; Agaricomycotina; Agaricomycetes; Agaricomycetidae; Agaricales; Strophariaceae; Galerina.



Function:		Dual function macrocyclase-peptidase involved in the biosynthesis of the highly toxic amanitin toxin family of macrocycles (PubMed:22202811, PubMed:28866879, PubMed:29051530). Cleaves peptide bonds on the C-terminal side of prolyl residues (PubMed:29051530). The enzyme first removes 10 residues from the N-terminus of a 35-residue substrate (PubMed:29051530). Conformational trapping of the 25 amino- acid peptide forces the enzyme to release this intermediate rather than proceed to macrocyclization (PubMed:29051530). The enzyme rebinds the 25 amino-acid peptide in a different conformation and catalyzes macrocyclization of the N-terminal eight residues (PubMed:28866879, PubMed:29051530). {ECO:0000269\|PubMed:22202811, ECO:0000269\|PubMed:28866879, ECO:0000269\|PubMed:29051530}.


Catalytic activity:		Reaction=Hydrolysis of Pro-\|-Xaa >> Ala-\|-Xaa in oligopeptides.; EC=3.4.21.26; Evidence={ECO:0000269\|PubMed:28866879, ECO:0000269\|PubMed:29051530};
Biophysicochemical properties:		Kinetic parameters: KM=23 uM for the full alpha-amanitin 35mer proprotein {ECO:0000269\|PubMed:29051530}; KM=51 uM for the 25mer IWGIGCNPWTAEHVDQTLASGNDIC {ECO:0000269\|PubMed:29051530}; KM=19 uM for the 25mer LWGIGCNPWTAEHVDQTLASGNDIC {ECO:0000269\|PubMed:29051530}; KM=8 uM for the 25mer IFGIGCNPWTAEHVDQTLASGNDIC {ECO:0000269\|PubMed:29051530}; KM=28 uM for the 25mer IWGIGSNPWTAEHVDQTLASGNDIC {ECO:0000269\|PubMed:29051530}; KM=10 uM for the 25mer IWGIGCNPWTAEHVDQTLASGNDIS {ECO:0000269\|PubMed:29051530}; KM=25 uM for the 19mer IWGIGCNPDQTLASGNDIC {ECO:0000269\|PubMed:29051530}; KM=380 uM for the 14mer IWGIGCNPWTAEHV {ECO:0000269\|PubMed:29051530}; KM=24.4 uM for the 13mer IWGIGCNPWTAEH {ECO:0000269\|PubMed:29051530};
Subunit:		Monomer. {ECO:0000250\|UniProtKB:P48147}.
Similarity:		Belongs to the peptidase S9A family. {ECO:0000305}.