Use of sulfolobus solfataricus PCNA subunit proteins to direct the assembly of multimeric enzyme complexes

Abstract

In nature, enzymes often form multienzyme complexes to enhance their catalytic efficiencies and, moreover, evolve into genetically fused multidomain enzymes. Inspired by a natural fusion cytochrome P450 (P450) containing a monooxygenase domain and a reductase domain, we have developed a heterotrimeric protein- utilized method to form a multienzyme complex composed of a bacterial P450 and its catalytically essential two redox proteins. Three distinct proliferating cell nuclear antigens (PCNAs) from Sulfolobus solfataricu s, each of which can be separately expressed, spontaneously form a heterotrimer. Fusion to the PCNAs enables complex formation of a bacterial P450 and two redox proteins through the self-assembling of the PCNAs and enhances the activity due to efficient electron transfer in the complex. This PCNAmediated multienzyme complex formation will be available for other multienzyme reactions. © Springer Science+Business Media New York 2013.