CO as a Substrate and Inhibitor of H+ Reduction for Mo-, V-, and Fe-Nitrogenase Isozymes

Alignment of α subunits of nitrogenase isozymes. Shown is<br> an alignment of α subunits of Mo-nitrogenase (PDB ID: 3U7Q), V-nitrogenase<br> (PDB ID: 5N6Y), and Fe-nitrogenase (sequence threaded<br> on to V-nitrogenase PDB ID: 5N6Y using Swiss-Model) highlighting<br> amino acid residues in the cofactor environment. The starting perspective is<br> looking down on the Fe2, 3, 6, 7 face of FeMoco and FeVco. S is in<br> yellow, Fe in orange, Mo in magenta, and V in pink with the homocitrate<br> to the right in grey. Side chains that are 100% conserved among the<br> isozymes are shown in green, whereas side chains where there is<br> variation in the residue in at least one isozyme are shown in red. The residue numbering refers<br> to Mo-nitrogenase. ChimeraX version 1.0 file.固氮酶同工酶α亚基的序列比对。本次展示的是钼铁固氮酶（Mo-nitrogenase，PDB ID: 3U7Q）、钒铁固氮酶（V-nitrogenase，PDB ID: 5N6Y）以及铁固氮酶（Fe-nitrogenase，其序列通过Swiss-Model穿模至钒铁固氮酶的PDB结构5N6Y）的α亚基比对结果，用以突出显示辅因子环境中的氨基酸残基。初始观察视角为俯视FeMoco（铁钼辅因子）与FeVco（铁钒辅因子）的Fe2、3、6、7面。硫原子（S）以黄色显示，铁原子（Fe）以橙色显示，钼原子（Mo）以洋红色显示，钒原子（V）以粉色显示，位于右侧的高柠檬酸以灰色显示。在所有同工酶中完全保守的侧链以绿色标注，而在至少一种同工酶中存在残基变异的侧链以红色标注。残基编号参照钼铁固氮酶进行设定。本文件为ChimeraX 1.0版本格式文件。