文章基本信息

标题：Crystal structure of linoleate 13R-manganese lipoxygenase in complex with an adhesion protein
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作者：Yang Chen ; Anneli Wennman ; Saeid Karkehabadi 等
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2016
卷号：57
期号：8
页码：1574-1588
DOI：10.1194/jlr.M069617
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：The crystal structure of 13 R -manganese lipoxygenase (MnLOX) of Gaeumannomyces graminis (Gg) in complex with zonadhesin of Pichia pastoris was solved by molecular replacement. Zonadhesin contains β-strands in two subdomains. A comparison of Gg-MnLOX with the 9 S -MnLOX of Magnaporthe oryzae (Mo) shows that the protein fold and the geometry of the metal ligands are conserved. The U-shaped active sites differ mainly due to hydrophobic residues of the substrate channel. The volumes and two hydrophobic side pockets near the catalytic base may sanction oxygenation at C-13 and C-9, respectively. Gly-332 of Gg-MnLOX is positioned in the substrate channel between the entrance and the metal center. Replacements with larger residues could restrict oxygen and substrate to reach the active site. C₁₈ fatty acids are likely positioned with C-11 between Mn²⁺OH₂ and Leu-336 for hydrogen ion and with one side of the 12 Z double bond shielded by Phe-337 to prevent antarafacial oxygenation at C-13 and C-11. Phe-347 is positioned at the end of the substrate channel and replacement with smaller residues can position C₁₈ fatty acids for oxygenation at C-9. Gg-MnLOX does not catalyze the sequential lipoxygenation of n -3 fatty acids in contrast to Mo-MnLOX, which illustrates the different configurations of their substrate channels.
关键词：lipoxygenase pathway ; metalloenzyme ; manganese superoxide dismutase ; oxylipins ; Pichia expression