Enzymes iron chelatase

Into mitochondrion having migrated— ing migrated Two vinyls first are formed Ifom propionates—propionates For protoporphyrin IX to be created—be created Coproporphyrinogen de saturates— saturate s Ferrous iron is finally inserted— ly inserted The enzyme now of course ferrochelatase— chelatase So two simple starting substances converted— ces converted To a complex haem which can t fail to amaze ... 

Perhaps the best-characterized example of this mechanism involves the synthesis of heme cofactors and their subsequent incorporation into various hemoproteins (see Iron Heme Proteins Electron Transport). Succinctly, enzyme-catalyzed reactions convert either succinyl-CoA or glutamate into 5-ammolevulinic acid. This molecule is further converted through a series of intermediates to form protoporphyrin IX, the metal-ffee cofactor, into which Fe is inserted by ferrochelatase. Analogous reactions are required for the synthesis of other tetrapyrrole macrocycles such as the cobalamins (see Cobalt Bu Enzymes Coenzymes), various types of chlorophylls, and the methanogen coenzyme F430 (containing Co, Mg, or Ni, respectively). Co- and Mg-chelatases have been described for insertion of these metals into the appropriate tetrapyrrolic ring structures. ... 

Macrocyclic tetrapyrrole compounds such as heme (iron), chlorophyll (magnesium), siroheme (iron), and E12 (cobalt) contain specific metal ions at the center of their tetrapyrrole rings [17]. Metal ion chelatases can be divided into two classes based on their structural architecture. Class 1 chelatases are heteromultimeric enzymes that require three gene products for efficient catalysis [18] of the ATP-dependent chelation reaction [19]. Enzymes in this class include chlorophyll and bacteriochlorophyll magnesium chelatases [18] and aerobic cobalt chelatase (CobNST) [20]. 

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