Functional domains of assimilatory nitrate reductases and nitrite reductases.

Biochemical investigation of nitrate assimilation enzymes spans the past four decades. With the molecular cloning of genes for nitrate reductases and nitrite reductases, exciting new prospects are developing for the study of these enzymes. As large, complex enzymes with multiple redox centers, these two types of reductases should help us gain understanding of structural, functional and evolutionary relationships among the diverse group of multicenter redox enzymes.