Microbes and Environments
Online ISSN : 1347-4405
Print ISSN : 1342-6311
ISSN-L : 1342-6311
Regular Paper
Two Distinct Enzymes Have Both Phytoene Desaturase and 3,4-Desaturase Activities Involved in Carotenoid Biosynthesis by the Extremely Halophilic Archaeon Haloarcula japonica
Rie Yatsunami Ai AndoNobuhiro MiyokoYing YangShinichi TakaichiSatoshi Nakamura
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2024 Volume 39 Issue 5 Article ID: ME24004


The extremely halophilic archaeon Haloarcula japonica accumulates the C50 carotenoid, bacterioruberin (BR). To reveal the BR biosynthetic pathway, unidentified phytoene desaturase candidates were functionally characterized in the present study. Two genes encoding the potential phytoene desaturases, c0507 and d1086, were found from the Ha. japonica genome sequence by a homology search using the Basic Local Align Search Tool. Disruption mutants of c0507 and d1086 and their complemented strains transformed with expression plasmids for c0507 and d1086 were subsequently constructed. High-performance liquid chromatography (HPLC) ana­lyses of carotenoids produced by these strains revealed that C0507 and D1086 were both bifunctional enzymes with the same activities as both phytoene desaturase (CrtI) and 3,4-desaturase (CrtD). C0507 and D1086 complemented each other during BR biosynthesis in Ha. japonica. This is the first study to identify two distinct enzymes with both CrtI and CrtD activities in an extremely halophilic archaeon.

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© 2024 by Japanese Society of Microbial Ecology / Japanese Society of Soil Microbiology / Taiwan Society of Microbial Ecology / Japanese Society of Plant Microbe Interactions / Japanese Society for Extremophiles.
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