An apoenzyme is the protein component of a cofactor-requiring enzyme before the required cofactor has been incorporated or after it has been removed. Cofactors such as iron–sulfur clusters, heme, and metal ions supply chemical functions within the assembled enzyme [1]. For complex iron–sulfur enzymes, maturation machinery builds the cofactor on an assembly scaffold and transfers it to a recipient protein lacking that component [2]. Iron–sulfur cluster maturation incorporates an assembled inorganic cluster into a recipient apoprotein through interactions with dedicated biogenesis components [3][4]. Assembly proteins and intracellular trafficking pathways coordinate this process for iron–sulfur proteins. The apoenzyme retains the polypeptide framework that accommodates the missing component, while full catalytic function requires completion of the corresponding active-site assembly [4][5].
- cofactor
- enzyme maturation
- apoprotein
- cofactor incorporation
References
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