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Structural insight into human variegate porphyria disease
Author(s) -
Qin Xiaohong,
Tan Ying,
Wang Lele,
Wang Zhifang,
Wang Baifan,
Wen Xin,
Yang Guangfu,
Xi Zhen,
Shen Yuequan
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.10-170811
Subject(s) - protoporphyrinogen oxidase , flavin adenine dinucleotide , heme , chemistry , protoporphyrin ix , biochemistry , mutation , cofactor , microbiology and biotechnology , biology , gene , enzyme , photodynamic therapy , organic chemistry
Human protoporphyrinogen IX oxidase (hPPO), a mitochondrial inner membrane protein, converts protoporphyrinogen IX to protoporphyrin IX in the heme biosynthetic pathway. Mutations in the hPPO gene cause the inherited human disease variegate porphyria (VP). In this study, we report the crystal structure of hPPO in complex with the coenzyme flavin adenine dinucleotide (FAD) and the inhibitor acifluor‐fen at a resolution of 1.9 Å. The structural and biochemical analyses revealed the molecular details of FAD and acifluorfen binding to hPPO as well as the interactions of the substrate with hPPO. Structural analysis and gel chromatography indicated that hPPO is a monomer rather than a homodimer in vitro. The founder‐effect mutation R59W in VP patients is most likely caused by a severe electrostatic hindrance in the hydrophilic binding pocket involving the bulky, hydro‐phobic indolyl ring of the tryptophan. Forty‐seven VP‐causing mutations were purified by chromatography and kinetically characterized in vitro. The effect of each mutation was demonstrated in the high‐resolution crystal structure.—Qin, X., Tan, Y., Wang, L., Wang, Z., Wang, B., Wen, X., Yang, G., Xi, Z., Shen, Y. Structural insight into human variegate porphyria disease. FASEB J. 25, 653–664 (2011). www.fasebj.org