Structure and mechanism of sanguinarine reductase, an enzyme of alkaloid detoxification.

ABSTRACT: Sanguinarine reductase is a plant enzyme that prevents the cytotoxic effects of benzophenanthridine alkaloids, which are the main phytoalexins of Papaveraceae. The enzyme catalyzes the reduction of sanguinarine, the most toxic benzophenanthridine, which re-enters the cytoplasm after its primary accumulation in the cell wall region has reached a threshold concentration. We present the sequence of the gene and protein of sanguinarine reductase isolated from cell cultures of Eschscholzia californica. High sequence similarities indicate that the enzyme evolved from a plant-specific branch of the ubiquitous Rossmann fold NAD(P)H/NAD(P)(+) binding reductases, with NADP-dependent epimerases or hydroxysteroid reductases as the most likely ancestors. Based on the x-ray structure of a close homolog,

SUBMITTER: Vogel M 

PROVIDER: S-EPMC2881765 | biostudies-literature | 2010 Jun

REPOSITORIES: biostudies-literature