Dataset Information

Sioxanthin, a novel glycosylated carotenoid, reveals an unusual subclustered biosynthetic pathway.

ABSTRACT: Members of the marine actinomycete genus Salinispora constitutively produce a characteristic orange pigment during vegetative growth. Contrary to the understanding of widespread carotenoid biosynthesis pathways in bacteria, Salinispora carotenoid biosynthesis genes are not confined to a single cluster. Instead, bioinformatic and genetic investigations confirm that four regions of the Salinispora tropica?CNB-440 genome, consisting of two gene clusters and two independent genes, contribute to the in vivo production of a single carotenoid. This compound, namely (2'S)-1'-(?-D-glucopyranosyloxy)-3',4'-didehydro-1',2'-dihydro-?,?-caroten-2'-ol, is novel and has been given the trivial name 'sioxanthin'. Sioxanthin is a C40 -carotenoid, glycosylated on one end of the molecule and containing an aryl moiety on the opposite end. Glycosylation is unusual among actinomycete carotenoids, and sioxanthin joins a rare group of carotenoids with polar and non-polar head groups. Gene sequence homology predicts that the sioxanthin biosynthetic pathway is present in all of the Salinispora as well as other members of the family Micromonosporaceae. Additionally, this study's investigations of clustering of carotenoid biosynthetic genes in heterotrophic bacteria show that a non-clustered genome arrangement is more common than previously suggested, with nearly half of the investigated genomes showing a non-clustered architecture.

SUBMITTER: Richter TK

PROVIDER: S-EPMC4755588 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Sioxanthin, a novel glycosylated carotenoid, reveals an unusual subclustered biosynthetic pathway.

Richter Taylor K S TK Hughes Chambers C CC Moore Bradley S BS

Environmental microbiology 20141211 6

Members of the marine actinomycete genus Salinispora constitutively produce a characteristic orange pigment during vegetative growth. Contrary to the understanding of widespread carotenoid biosynthesis pathways in bacteria, Salinispora carotenoid biosynthesis genes are not confined to a single cluster. Instead, bioinformatic and genetic investigations confirm that four regions of the Salinispora tropica CNB-440 genome, consisting of two gene clusters and two independent genes, contribute to the ...[more]

PMID: 25329237

Similar Datasets

Project description:Carotenoids are produced by all photosynthetic organisms, where they play essential roles in light harvesting and photoprotection. The carotenoid biosynthetic pathway of diatoms is largely unstudied, but is of particular interest because these organisms have a very different evolutionary history with respect to the Plantae and are thought to be derived from an ancient secondary endosymbiosis between heterotrophic and autotrophic eukaryotes. Furthermore, diatoms have an additional xanthophyll-based cycle for dissipating excess light energy with respect to green algae and higher plants. To explore the origins and functions of the carotenoid pathway in diatoms we searched for genes encoding pathway components in the recently completed genome sequences of two marine diatoms. Consistent with the supplemental xanthophyll cycle in diatoms, we found more copies of the genes encoding violaxanthin de-epoxidase (VDE) and zeaxanthin epoxidase (ZEP) enzymes compared with other photosynthetic eukaryotes. However, the similarity of these enzymes with those of higher plants indicates that they had very probably diversified before the secondary endosymbiosis had occurred, implying that VDE and ZEP represent early eukaryotic innovations in the Plantae. Consequently, the diatom chromist lineage likely obtained all paralogues of ZEP and VDE genes during the process of secondary endosymbiosis by gene transfer from the nucleus of the algal endosymbiont to the host nucleus. Furthermore, the presence of a ZEP gene in Tetrahymena thermophila provides the first evidence for a secondary plastid gene encoded in a heterotrophic ciliate, providing support for the chromalveolate hypothesis. Protein domain structures and expression analyses in the pennate diatom Phaeodactylum tricornutum indicate diverse roles for the different ZEP and VDE isoforms and demonstrate that they are differentially regulated by light. These studies therefore reveal the ancient origins of several components of the carotenoid biosynthesis pathway in photosynthetic eukaryotes and provide information about how they have diversified and acquired new functions in the diatoms.

Dataset Information

Sioxanthin, a novel glycosylated carotenoid, reveals an unusual subclustered biosynthetic pathway.

Publications

Sioxanthin, a novel glycosylated carotenoid, reveals an unusual subclustered biosynthetic pathway.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets