{
    "accession": "MITE0000428",
    "status": "active",
    "comment": "CtcP is a flavin-dependent halogenase involved in the biosynthesis of the antibiotic chlortetracycline.",
    "changelog": [
        {
            "version": "1",
            "date": "2026-06-26",
            "contributors": [
                "0009-0008-8086-5325"
            ],
            "reviewers": [
                "0000-0001-6534-6609"
            ],
            "comment": "New entry. Fixed reaction SMARTS and added additional comments."
        }
    ],
    "enzyme": {
        "name": "CtcP",
        "description": "Halogenase",
        "references": [
            "doi:10.1016/j.ymben.2013.06.003"
        ],
        "auxiliaryEnzymes": [
            {
                "name": "CtcQ",
                "description": "Flavin reductase",
                "databaseIds": {
                    "uniprot": "UPI0000602190",
                    "genpept": "AEI98660.1"
                }
            }
        ],
        "databaseIds": {
            "uniprot": "UPI00038473B8",
            "genpept": "AEI98659.1",
            "mibig": "BGC0000209"
        },
        "cofactors": {
            "organic": [
                "FAD"
            ]
        }
    },
    "reactions": [
        {
            "tailoring": [
                "Halogenation"
            ],
            "description": "CtcP catalyzes the regioselective C-7 chlorination of the tetracycline scaffold to produce chlortetracycline. 4-epi-tetracyclin (4R) is a non-substrate.",
            "reactionSMARTS": "[#6:1]-[#7:2](/[#6@:4]1-[#6:32]2-[#6@@:13](-[#6:15](=[#6:17]3-[#6:30](-[#6:31]-2)-[#6@@:27](\\[#8:29])(-[#6:28])-[#6:26]2:[#6:20](:[#6:21](:[#6:23]:[#6:24]:[#6:25]:2)-[#8:22])-[#6:18]-3=[#8:19])-[#8:16])(/[#8:14])-[#6:11](=[#8:12])-[#6:7](-[#6:8](=[#8:10])-[#7:9])=[#6:5]-1-[#8:6])-[#6:3]>>[#6:1]-[#7:2](/[#6@:4]1-[#6:32]2-[#6@@:13](-[#6:15](=[#6:17]3-[#6:30](-[#6:31]-2)-[#6@@:27](\\[#8:29])(-[#6:28])-[#6:26]2:[#6:20](:[#6:21](:[#6:23]:[#6:24]:[#6:25]:2-[Cl])-[#8:22])-[#6:18]-3=[#8:19])-[#8:16])(/[#8:14])-[#6:11](=[#8:12])-[#6:7](-[#6:8](=[#8:10])-[#7:9])=[#6:5]-1-[#8:6])-[#6:3]",
            "reactions": [
                {
                    "substrate": "CN(C)[C@@H]1C(O)=C(C(N)=O)C(=O)[C@@]2(O)C(O)=C3C(=O)c4c(O)cccc4[C@@](C)(O)C3CC12",
                    "products": [
                        "CN(C)[C@@H]1C(O)=C(C(N)=O)C(=O)[C@@]2(O)C(O)=C3C(=O)c4c(O)ccc(Cl)c4[C@@](C)(O)C3CC12"
                    ],
                    "isIntermediate": false,
                    "description": "Chlorination of the (4S) tetracycline as last step in the chlortetracyclin biosynthetic pathway."
                }
            ],
            "evidence": {
                "evidenceCode": [
                    "Heterologous expression",
                    "In vitro assay",
                    "Knock-out studies"
                ],
                "references": [
                    "doi:10.1016/j.ymben.2013.06.003"
                ]
            }
        }
    ]
}