{
    "accession": "MITE0000405",
    "status": "active",
    "comment": "Mononuclear non-heme iron enzyme with high substrate- and reaction promiscuity, including halogenation (Cl, Br), oxygenation, and vinyl-chloride formation. Consists of unusual three-domain structure with N-terminal catalytic halogenase domain, an ACBP, and an substrate-anchoring ACP.",
    "changelog": [
        {
            "version": "1",
            "date": "2026-06-10",
            "contributors": [
                "0009-0000-8651-1669"
            ],
            "reviewers": [
                "0000-0001-6534-6609"
            ],
            "comment": "New entry."
        }
    ],
    "enzyme": {
        "name": "HctB",
        "description": "Fatty acyl halogenase",
        "references": [
            "doi:10.1002/cbic.201300345"
        ],
        "databaseIds": {
            "uniprot": "Q1EDB4",
            "genpept": "AAY42394.1",
            "mibig": "BGC0001000"
        },
        "cofactors": {
            "organic": [
                "a-Ketoglutaric acid"
            ],
            "inorganic": [
                "Fe"
            ]
        }
    },
    "reactions": [
        {
            "tailoring": [
                "Halogenation"
            ],
            "description": "Bicyclic halogenation through C5 radical intermediate product in the hectochlorin biosynthetic pathway.",
            "reactionSMARTS": "[*]-[#16:2]-[#6:3](=[#8:9])-[#6:4]-[#6:5]-[#6:6]-[#6:7]-[#6:8]>>[*]-[#16:2]-[#6:3](=[#8:9])-[#6:4]-[#6:5]-[#6:6]-[#6:7](-[Cl])(-[Cl])-[#6:8]",
            "reactions": [
                {
                    "substrate": "*SC(=O)CCCCC",
                    "products": [
                        "*SC(=O)CCCC(C)(Cl)Cl"
                    ],
                    "isIntermediate": true,
                    "description": "C5 dichlorination of fatty acyl substrate."
                }
            ],
            "evidence": {
                "evidenceCode": [
                    "Heterologous expression",
                    "In vitro assay"
                ],
                "references": [
                    "doi:10.1002/cbic.201300345"
                ]
            }
        },
        {
            "tailoring": [
                "Dehydrogenation",
                "Halogenation"
            ],
            "description": "Bicyclic halogenation and dehydrogenation through C5 radical intermediate product  in the hectochlorin biosynthetic pathway.",
            "reactionSMARTS": "[*]-[#16:2]-[#6:3](=[#8:9])-[#6:4]-[#6:5]-[#6:6]-[#6:7]-[#6:8]>>[*]-[#16:2]-[#6:3](=[#8:9])-[#6:4]-[#6:5]-[#6:6]=[#6:7](-[Cl])-[#6:8]",
            "reactions": [
                {
                    "substrate": "*SC(=O)CCCCC",
                    "products": [
                        "*SC(=O)CCC=C(C)Cl"
                    ],
                    "isIntermediate": true,
                    "description": "Single C5 chlorination and C4, C5 dehydrogenation resulting in a vinyl-chloride product of fatty acyl substrate."
                }
            ],
            "evidence": {
                "evidenceCode": [
                    "Heterologous expression",
                    "In vitro assay"
                ],
                "references": [
                    "doi:10.1002/cbic.201300345"
                ]
            }
        },
        {
            "tailoring": [
                "Monooxygenation",
                "Oxidation"
            ],
            "description": "Bicyclic monooxygenation through C5 radical intermediate product  in the hectochlorin biosynthetic pathway.",
            "reactionSMARTS": "[*]-[#16:2]-[#6:3](=[#8:9])-[#6:4]-[#6:5]-[#6:6]-[#6:7]-[#6:8]>>[*]-[#16:2]-[#6:3](=[#8:9])-[#6:4]-[#6:5]-[#6:6]-[#6:7](=[#8])-[#6:8]",
            "reactions": [
                {
                    "substrate": "*SC(=O)CCCCC",
                    "products": [
                        "*SC(=O)CCCC(C)=O"
                    ],
                    "isIntermediate": true,
                    "description": "C5 monoxygenation of fatty acyl substrate, resulting in keto-moiety."
                }
            ],
            "evidence": {
                "evidenceCode": [
                    "Heterologous expression",
                    "In vitro assay"
                ],
                "references": [
                    "doi:10.1002/cbic.201300345"
                ]
            }
        }
    ]
}