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Identification and characterization of the geranylgeranyl diphosphate synthase in D einococcus radiodurans
Author(s) -
Liu C.,
Sun Z.,
Shen S.,
Lin L.,
Li T.,
Tian B.,
Hua Y.
Publication year - 2014
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/lam.12181
Subject(s) - deinococcus radiodurans , biochemistry , biology , biosynthesis , mutant , escherichia coli , amino acid , carotenoid , gene , atp synthase
D einococcus radiodurans strain R 1 utilizes multiple antioxidants including a unique carotenoid, deinoxanthin, to fight again oxidative stress. Most of the enzymes involved in the deinoxanthin biosynthetic pathway have been identified. However, the enzyme catalysing the synthesis of geranylgeranyl diphosphate ( GGPP ), which is a precursor of carotenoid biosynthesis, has yet to be identified. Two putative isoprenyl diphosphate synthases ( IPPS ) homologues ( DR 1395 and DR 932) were screened out by analysis of conserved amino acid regions, and their biochemical functions were investigated. Gene mutation, gene expression in E scherichia coli and analysis of carotenoid products were used to investigate the functions of these candidates. The results suggested that DR 1395 encodes the protein for GGPP synthesis. Site‐directed mutant analysis indicated that the amino acid composition of and around the first aspartate‐rich motif is vital for GGPP synthase function. Significance and Impact of the Study D einococcus radiodurans strain R 1 produces a unique carotenoid product, deinoxanthin, as an antioxidant. In this study, DR 1395 was identified as the gene encoding geranylgeranyl diphosphate synthase ( GGPPS ) for entrance to deinoxanthin biosynthesis in D . radiodurans . Moreover, site‐directed mutagenesis studies on DR 1395 identified the effect of amino acid composition of the aspartate‐rich motif on the production of this carotenoid. This study demonstrated the entrance step in the deinoxanthin biosynthetic pathway. These results can be useful in genetic engineering strategies for deinoxanthin production including enhancement of GGPPS gene expression in D . radiodurans .