Canniffe, D.P., Thweatt, J.L., Gomez Maqueo Chew, A. et al. (2 more authors) (2018) A paralog of a bacteriochlorophyll biosynthesis enzyme catalyzes the formation of 1,2-dihydro-carotenoids in green sulfur bacteria. Journal of Biological Chemistry, 293 (39). pp. 15233-15242. ISSN 0021-9258
Abstract
Chlorobaculum tepidum, a green sulfur bacterium, utilizes chlorobactene as its major carotenoid, and this organism also accumulates a reduced form of this monocyclic pigment, 1',2'-dihydrochlorobactene. The protein catalyzing this reduction is the last unidentified enzyme in the biosynthetic pathways for all of the green sulfur bacterial pigments used for photosynthesis. The genome of Chlorobaculum tepidum contains two paralogous genes encoding members of the FixC family of flavoproteins: bchP, that has been shown to encode an enzyme of bacteriochlorophyll biosynthesis; and bchO, for which a function has not been assigned. Here we demonstrate that a bchO mutant is unable to synthesize 1',2'-dihydrochlorobactene, and when bchO is heterologously expressed in a neurosporene-producing mutant of the purple bacterium, Rhodobactersphaeroides, the encoded protein is able to catalyze the formation of 1,2-dihydroneurosporene, the major carotenoid of the only other organism reported to synthesize 1,2-dihydrocarotenoids, Blastochloris viridis Identification of this enzyme completes the pathways for the synthesis of photosynthetic pigments in Chlorobiaceae, and accordingly and consistent with its role in carotenoid biosynthesis, we propose to rename the gene, cruI Notably, the absence of cruI in Blastochloris viridis indicates that a second 1,2-carotenoid reductase, which is structurally unrelated to CruI (BchO), must exist in nature. The evolution of this carotenoid reductase in green sulfur bacteria is discussed herein.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2018 Canniffe et al. Published by The American Society for Biochemistry and Molecular Biology, Inc. This is an open access article under the CC BY license. (http://creativecommons.org/licenses/by/4.0/) |
Keywords: | Blastochloris viridis; Chlorobaculum tepidum; Rhodobacter sphaeroides; bacterial genetics; carotenoid; energy metabolism; green sulfur bacterium; photosynthesis; photosynthetic pigment |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Biosciences (Sheffield) > Department of Molecular Biology and Biotechnology (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 11 Oct 2018 08:29 |
Last Modified: | 10 May 2024 10:22 |
Status: | Published |
Publisher: | American Society for Biochemistry and Molecular Biology |
Refereed: | Yes |
Identification Number: | 10.1074/jbc.RA118.004672 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:136825 |