气候变化领域集成服务门户(CCPortal): Structure and assembly of the diiron cofactor in the heme-oxygenase–like domain of the N-nitrosourea

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DOI	10.1073/pnas.2015931118
	Structure and assembly of the diiron cofactor in the heme-oxygenase–like domain of the N-nitrosourea–producing enzyme SznF
	McBride M.J.; Pope S.R.; Hu K.; Denise Okafor C.; Balskus E.P.; Martin Bollinger J.; Boal A.K.
发表日期	2021
ISSN	00278424
卷号	118 期号:4
英文摘要	In biosynthesis of the pancreatic cancer drug streptozotocin, the tridomain nonheme-iron oxygenase SznF hydroxylates Nδ and Nω′ of Nω-methyl-L-arginine before oxidatively rearranging the triply modified guanidine to the N-methyl-N-nitrosourea pharmacophore. A previously published structure visualized the monoiron cofactor in the enzyme’s C-terminal cupin domain, which promotes the final rearrangement, but exhibited disorder and minimal metal occupancy in the site of the proposed diiron cofactor in the N-hydroxylating heme-oxygenase–like (HO-like) central domain. We leveraged our recent observation that the N-oxygenating μ-peroxodiiron(III/III) intermediate can form in the HO-like domain after the apo protein self-assembles its diiron(II/II) cofactor to solve structures of SznF with both of its iron cofactors bound. These structures of a biochemically validated member of the emerging heme-oxygenase–like diiron oxidase and oxygenase (HDO) superfamily with intact diiron cofactor reveal both the large-scale conformational change required to assemble the O2-reactive Fe2(II/II) complex and the structural basis for cofactor instability—a trait shared by the other validated HDOs. During cofactor (dis)assembly, a ligand-harboring core helix dynamically (un)folds. The diiron cofactor also coordinates an unanticipated Glu ligand contributed by an auxiliary helix implicated in substrate binding by docking and molecular dynamics simulations. The additional carboxylate ligand is conserved in another N-oxygenating HDO but not in two HDOs that cleave carbon–hydrogen and carbon–carbon bonds to install olefins. Among ∼9,600 sequences identified bioinformatically as members of the emerging HDO superfamily, ∼25% conserve this additional carboxylate residue and are thus tentatively assigned as N-oxygenases. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Bioinformatics; N-oxygenase; Streptozotocin; X-ray crystallography
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180914
作者单位	Department of Chemistry, Pennsylvania State University, University Park, PA 16802, United States; Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, United States; Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, United States
推荐引用方式 GB/T 7714	McBride M.J.,Pope S.R.,Hu K.,等. Structure and assembly of the diiron cofactor in the heme-oxygenase–like domain of the N-nitrosourea–producing enzyme SznF[J],2021,118(4).
APA	McBride M.J..,Pope S.R..,Hu K..,Denise Okafor C..,Balskus E.P..,...&Boal A.K..(2021).Structure and assembly of the diiron cofactor in the heme-oxygenase–like domain of the N-nitrosourea–producing enzyme SznF.Proceedings of the National Academy of Sciences of the United States of America,118(4).
MLA	McBride M.J.,et al."Structure and assembly of the diiron cofactor in the heme-oxygenase–like domain of the N-nitrosourea–producing enzyme SznF".Proceedings of the National Academy of Sciences of the United States of America 118.4(2021).