A tale of two reductases: extending the bacteriochlorophyll biosynthetic pathway in E. coli.

The creation of a synthetic microbe that can harvest energy from sunlight to drive its metabolic processes is an attractive approach to the economically viable biosynthetic production of target compounds. Our aim is to design and engineer a genetically tractable non-photosynthetic microbe to produce...

Full description

Saved in:
Bibliographic Details
Main Authors: Ilya B Tikh, Maureen B Quin, Claudia Schmidt-Dannert
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2014-01-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0089734&type=printable
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850024075904155648
author Ilya B Tikh
Maureen B Quin
Claudia Schmidt-Dannert
author_facet Ilya B Tikh
Maureen B Quin
Claudia Schmidt-Dannert
author_sort Ilya B Tikh
collection DOAJ
description The creation of a synthetic microbe that can harvest energy from sunlight to drive its metabolic processes is an attractive approach to the economically viable biosynthetic production of target compounds. Our aim is to design and engineer a genetically tractable non-photosynthetic microbe to produce light-harvesting molecules. Previously we created a modular, multienzyme system for the heterologous production of intermediates of the bacteriochlorophyll (BChl) pathway in E. coli. In this report we extend this pathway to include a substrate promiscuous 8-vinyl reductase that can accept multiple intermediates of BChl biosynthesis. We present an informative comparative analysis of homologues of 8-vinyl reductase from the model photosynthetic organisms Rhodobacter sphaeroides and Chlorobaculum tepidum. The first purification of the enzymes leads to their detailed biochemical and biophysical characterization. The data obtained reveal that the two 8-vinyl reductases are substrate promiscuous, capable of reducing the C8-vinyl group of Mg protoporphyrin IX, Mg protoporphyrin IX methylester, and divinyl protochlorophyllide. However, activity is dependent upon the presence of chelated Mg(2+) in the porphyrin ring, with no activity against non-Mg(2+) chelated intermediates observed. Additionally, CD analyses reveal that the two 8-vinyl reductases appear to bind the same substrate in a different fashion. Furthermore, we discover that the different rates of reaction of the two 8-vinyl reductases both in vitro, and in vivo as part of our engineered system, results in the suitability of only one of the homologues for our BChl pathway in E. coli. Our results offer the first insights into the different functionalities of homologous 8-vinyl reductases. This study also takes us one step closer to the creation of a nonphotosynthetic microbe that is capable of harvesting energy from sunlight for the biosynthesis of molecules of choice.
format Article
id doaj-art-b6639917796541bca0407d66c752d5f2
institution DOAJ
issn 1932-6203
language English
publishDate 2014-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj-art-b6639917796541bca0407d66c752d5f22025-08-20T03:01:13ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-0192e8973410.1371/journal.pone.0089734A tale of two reductases: extending the bacteriochlorophyll biosynthetic pathway in E. coli.Ilya B TikhMaureen B QuinClaudia Schmidt-DannertThe creation of a synthetic microbe that can harvest energy from sunlight to drive its metabolic processes is an attractive approach to the economically viable biosynthetic production of target compounds. Our aim is to design and engineer a genetically tractable non-photosynthetic microbe to produce light-harvesting molecules. Previously we created a modular, multienzyme system for the heterologous production of intermediates of the bacteriochlorophyll (BChl) pathway in E. coli. In this report we extend this pathway to include a substrate promiscuous 8-vinyl reductase that can accept multiple intermediates of BChl biosynthesis. We present an informative comparative analysis of homologues of 8-vinyl reductase from the model photosynthetic organisms Rhodobacter sphaeroides and Chlorobaculum tepidum. The first purification of the enzymes leads to their detailed biochemical and biophysical characterization. The data obtained reveal that the two 8-vinyl reductases are substrate promiscuous, capable of reducing the C8-vinyl group of Mg protoporphyrin IX, Mg protoporphyrin IX methylester, and divinyl protochlorophyllide. However, activity is dependent upon the presence of chelated Mg(2+) in the porphyrin ring, with no activity against non-Mg(2+) chelated intermediates observed. Additionally, CD analyses reveal that the two 8-vinyl reductases appear to bind the same substrate in a different fashion. Furthermore, we discover that the different rates of reaction of the two 8-vinyl reductases both in vitro, and in vivo as part of our engineered system, results in the suitability of only one of the homologues for our BChl pathway in E. coli. Our results offer the first insights into the different functionalities of homologous 8-vinyl reductases. This study also takes us one step closer to the creation of a nonphotosynthetic microbe that is capable of harvesting energy from sunlight for the biosynthesis of molecules of choice.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0089734&type=printable
spellingShingle Ilya B Tikh
Maureen B Quin
Claudia Schmidt-Dannert
A tale of two reductases: extending the bacteriochlorophyll biosynthetic pathway in E. coli.
PLoS ONE
title A tale of two reductases: extending the bacteriochlorophyll biosynthetic pathway in E. coli.
title_full A tale of two reductases: extending the bacteriochlorophyll biosynthetic pathway in E. coli.
title_fullStr A tale of two reductases: extending the bacteriochlorophyll biosynthetic pathway in E. coli.
title_full_unstemmed A tale of two reductases: extending the bacteriochlorophyll biosynthetic pathway in E. coli.
title_short A tale of two reductases: extending the bacteriochlorophyll biosynthetic pathway in E. coli.
title_sort tale of two reductases extending the bacteriochlorophyll biosynthetic pathway in e coli
url https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0089734&type=printable
work_keys_str_mv AT ilyabtikh ataleoftworeductasesextendingthebacteriochlorophyllbiosyntheticpathwayinecoli
AT maureenbquin ataleoftworeductasesextendingthebacteriochlorophyllbiosyntheticpathwayinecoli
AT claudiaschmidtdannert ataleoftworeductasesextendingthebacteriochlorophyllbiosyntheticpathwayinecoli
AT ilyabtikh taleoftworeductasesextendingthebacteriochlorophyllbiosyntheticpathwayinecoli
AT maureenbquin taleoftworeductasesextendingthebacteriochlorophyllbiosyntheticpathwayinecoli
AT claudiaschmidtdannert taleoftworeductasesextendingthebacteriochlorophyllbiosyntheticpathwayinecoli