Insight into the molecular evolution of two tropinone reductases.

@article{Nakajima1999InsightIT,
  title={Insight into the molecular evolution of two tropinone reductases.},
  author={Keiji Nakajima and Yuichi Oshita and Yasuyuki Yamada and Takashi Hashimoto},
  journal={Bioscience, biotechnology, and biochemistry},
  year={1999},
  volume={63 10},
  pages={1819-22}
}
In tropane alkaloid biosynthesis, two tropinone reductases produce different stereoisomers from a common substrate, tropinone. The two enzymes share 64% of identical amino acids, and highly homologous proteins with variable substrate-binding residues have also been found in tropane alkaloid non-producing species. This exemplifies a simple evolutionary process that plants have taken to acquire a new secondary metabolic pathway.