Stereoselective C3-substituent modification and substrate channeling by oxidoreductase BchC in bacteriochlorophyll a biosynthesis

FEBS Letters

article

Misato Teramura¹  Yusuke Tsukatani²  Jiro Harada³  Mitsuaki Hirose¹  Hitoshi Tamiaki¹ 

[1]Graduate School of Life Sciences, Ritsumeikan University

[2]Research and Development Center for Marine Biosciences, Japan Agency for Marine-Earth Science and Technology (JAMSTEC)

[3]Department of Medical Biochemistry, Kurume University School of Medicine

关键词: bacteriochlorophyll;    dehydrogenase;    green sulfur bacterium;    hydratase;    purple bacterium;   

DOI  :  10.1002/1873-3468.13372

来源: John Wiley & Sons Ltd.

【 摘 要 】

We report the in vitro activity of recombinant BchC oxidoreductase involved in bacteriochlorophyll a biosynthesis. BchC of Rhodobacter capsulatus preferentially oxidizes 31 R-3-(1-hydroxyethyl)-chlorophyllide a and 31 R-3-(1- hydroxyethyl)-bacteriochlorophyllide a in the presence of NAD+ to 3-acetylchlorophyllide a and bacteriochlorophyllide a, respectively, leaving the unreacted 31 S-epimers. In the reverse reaction, BchC with NADH predominately produces 31 R-epimeric alcohols from the 3-acetyl-(bacterio)chlorins. BchC of Chlorobaculum tepidum demonstrates the same 31 R-selectivity, suggesting that utilization of 31 R-epimers in BchC-catalyzed reductions may be conserved across different phyla of photosynthetic bacteria. Additionally, the presence of BchC accelerates the 3-vinyl hydration by BchF hydratase of Chlorobaculum tepidum during conversion of chlorophyllide a to 3-acetyl-chlorophyllide a through 3-(1-hydroxyethyl)-chlorophyllide a, indicating that these enzymes work cooperatively to promote efficient bacteriochlorophyll a biosynthesis.

【 授权许可】

Unknown