Nonhaem Iron Enzymes

FIGURE 13.25 Three-dimensional structures of di-iron proteins. The iron-binding subunits of (a) haemerythrin, (b) bacterioferritin, (c) rubryerythrin (the FeS centre is on the top), (d) ribonucleotide reductase R2 subunit, (e) stearoyl-acyl carrier protein A -desaturase, and (f) methane monooxygenase hydroxylase a-subunit. (From Nordlund Eklund, 1995. Copyright 1995, with permission from Elsevier.) 

FIGURE 13.27 Structures of sMMOH components and proposed reaction cycle, (a) MMOH (b) the MMOR FAD and ferredoxin (Fd) domains and (c) MMOB. In MMOH, the a, P, and y subunits are coloured blue, green, and purple, respectively. Iron, sulfur, and FAD are coloured orange, yellow, and red, respectively, and are depicted as spheres. The MMO reaction cycle is shown on the right., with atoms coloured [Fe (black), C (grey), O (red), and N (blue)]. (From Sazinsky Lippard, 2006. Copyright 2006 American Chemical Society.) 

FIGURE 13.28 Conserved residues in Class I RNR, which compose the putative PCET pathway for radical transport from Y122 in R2 to C439 in the R1 active site. (Seyedsayamdost, Yee, Reece, Nocera, Stubbe, 2006. Copyright (2006) American Chemical Society.) 

Andreou, A., Feussner, I. (2009). Lipoxygenases — structure and reaction mechanism. Phytochemistry, 70, 644—649. 

Mulliez, E., Arragain, S., Forouhar, F, Hunt, J. R, Fontecave, M. (2010). S-Adenosylmethionine-dependent radical-based modification of biological macromolecules. Current Opinion in Structural Biology, 20, 684—692. 

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Other Iron-Containing Proteins Dinuclear Nonhaem Iron Enzymes... 

FIGURE 13.20 Reactions catalysed by each of the five families of mononuclear nonhaem iron enzymes with a 2-His-l-carboxylate facial triad. Dioxygen is labelled to indicate the fate of each oxygen atom. Adapted from Koehntop, Emerson, Que, 2005.)... 

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