title: Complete biosynthetic pathway of the C50 carotenoid bacterioruberin from lycopene in the extremely halophilic archaeon Haloarcula japonica.
abstract: Haloarcula japonica, an extremely halophilic archaeon that requires high concentrations of NaCl for growth, accumulates the C50 carotenoid bacterioruberin (BR). By homology analysis, a gene cluster, including c0507, c0506, and c0505, was found and predicted to be involved in the synthesis of bacterioruberin. To elucidate the function of the encoded enzymes, we constructed Ha. japonica mutants of these genes and analyzed carotenoids produced by the mutants. Our research showed that c0507, c0506, and c0505 encoded a carotenoid 3,4-desaturase (CrtD), a bifunctional lycopene elongase and 1,2-hydratase (LyeJ), and a C50 carotenoid 2",3"-hydratase (CruF), respectively. The above three carotenoid biosynthetic enzymes catalyze the reactions that convert lycopene to bacterioruberin in Ha. japonica. This is the first identification of functional CrtD and CruF in archaea and elucidation of the complete biosynthetic pathway of bacterioruberin from lycopene.
  
  
  OBJECTIVE
  Haloarcula japonica, an extremely halophilic archaeon, accumulates the C50 carotenoid bacterioruberin (BR). In this study, we have identified three BR biosynthetic enzymes and have elucidated their functions. Among them, two enzymes were found in an archaeon for the first time. Our results revealed the biosynthetic pathway responsible for production of BR in Ha. japonica and provide a basis for investigating carotenoid biosynthetic pathways in other extremely halophilic archaea. Elucidation of the carotenoid biosynthetic pathway in Ha. japonica may also prove useful for producing the C50 carotenoid BR efficiently by employing genetically modified haloarchaeal strains.
authors.affiliation: Department of Bioengineering, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: Ying
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Bioengineering, Tokyo Institute of Technology, Yokohama, Japan yatsunami.r.aa@m.titech.ac.jp.
authors.forename: Rie
authors.initials: R
authors.lastname: Yatsunami
authors.affiliation: Department of Bioengineering, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Ando
authors.affiliation: Department of Bioengineering, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Miyoko
authors.affiliation: Department of Bioengineering, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Fukui
authors.affiliation: Department of Biology, Nippon Medical School, Musashino, Tokyo, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Takaichi
authors.affiliation: Department of Bioengineering, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakamura
mesh_terms: D053898:Biosynthetic Pathways / Q000235:genetics*; D002338:Carotenoids / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism*; D017353:Gene Deletion; D019613:Haloarcula / Q000235:genetics* / Q000378:metabolism*; D000077276:Lycopene; D005810:Multigene Family; D012965:Sodium Chloride / Q000378:metabolism
chemical_list: C002951:bacterioruberin; D002338:Carotenoids; D012965:Sodium Chloride; D000077276:Lycopene