{
    "accession": "MITE0000439",
    "status": "active",
    "comment": "StrB installs the Lys-to-Trp crosslink in the biosynthesis of streptide",
    "changelog": [
        {
            "version": "1",
            "date": "2026-06-03",
            "contributors": [
                "0009-0008-8086-5325"
            ],
            "reviewers": [
                "0000-0002-4540-6501"
            ],
            "comment": "New entry."
        }
    ],
    "enzyme": {
        "name": "StrB",
        "description": "Radical SAM enzyme",
        "references": [
            "doi:10.1038/nchem.2237"
        ],
        "databaseIds": {
            "uniprot": "UPI0000E5643D",
            "genpept": "ABJ66529.1",
            "mibig": "BGC0001209"
        },
        "cofactors": {
            "organic": [
                "SAM"
            ],
            "inorganic": [
                "FeS"
            ]
        }
    },
    "reactions": [
        {
            "tailoring": [
                "Biaryl bond formation",
                "Cyclization"
            ],
            "description": "StrB installs the Lys-to-Trp crosslink through a C-C bond between the C\u03b2 of Lys and the aromatic C7 of Trp",
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            "reactions": [
                {
                    "substrate": "CSCC[C@H](NC(=O)[C@H](CO)NC(=O)[C@H](CO)NC(=O)[C@H](CO)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CC(C)C)NC(=O)[C@@H](NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CO)NC(=O)[C@@H](N)CCSC)C(C)C)C(=O)N[C@@H](C)C(=O)N[C@@H](CCCCN)C(=O)NCC(=O)N[C@@H](CC(=O)O)C(=O)NCC(=O)N[C@@H](Cc1c[nH]c2ccccc12)C(=O)N[C@@H](CCCCN)C(=O)N[C@H](C(=O)N[C@@H](CCSC)C(=O)N[C@@H](C)C(=O)N[C@@H](CCCCN)C(=O)NCC(=O)N[C@@H](CC(=O)O)C(=O)NCC(=O)N[C@@H](Cc1c[nH]c2ccccc12)C(=O)N[C@@H](CCC(=O)O)C(=O)O)C(C)C",
                    "products": [
                        "CSCC[C@H](NC(=O)[C@H](CO)NC(=O)[C@H](CO)NC(=O)[C@H](CO)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CC(C)C)NC(=O)[C@@H](NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CO)NC(=O)[C@@H](N)CCSC)C(C)C)C(=O)N[C@@H](C)C(=O)N[C@@H]1C(=O)NCC(=O)N[C@@H](CC(=O)O)C(=O)NCC(=O)N[C@H](C(=O)N[C@@H](CCCCN)C(=O)N[C@H](C(=O)N[C@@H](CCSC)C(=O)N[C@@H](C)C(=O)N[C@@H](CCCCN)C(=O)NCC(=O)N[C@@H](CC(=O)O)C(=O)NCC(=O)N[C@@H](Cc2c[nH]c3ccccc23)C(=O)N[C@@H](CCC(=O)O)C(=O)O)C(C)C)Cc2c[nH]c3c(cccc23)C1CCCN"
                    ],
                    "isIntermediate": true,
                    "description": "The strA product, 30mer precursor peptide is acted upon by StrB to install the Lys-to-Trp crosslink. The cross-linked product is then further processed likely involving StrC and proteases, to give the final 9-mer cyclic streptide."
                }
            ],
            "evidence": {
                "evidenceCode": [
                    "Heterologous expression",
                    "In vitro assay",
                    "Knock-out studies",
                    "Site-directed mutagenesis"
                ],
                "references": [
                    "doi:10.1038/nchem.2237"
                ]
            }
        }
    ]
}