Molecular cloning and sequence analysis of the crtB gene of Thermus thermophilus HB27, an extreme thermophile producing carotenoid pigments.
We have cloned and sequenced a 1.5-kb chromosomal fragment of Thermus thermophilus which promoted the overproduction of carotenoids in T. thermophilus. An open reading frame (ORF-A) coding for a polypeptide with 289 amino acids was responsible for carotenoid overproduction. The putative ORF-A protein showed significant homology with the amino acid sequences of crtB gene products (phytoene syntheses) of other microorganisms. The clone containing the ORF-A on a multicopy plasmid produced about three times as much carotenoid as that produced by the host strain, suggesting that the crtB gene product is a rate-limiting enzyme for carotenoid biosynthesis in T. thermophilus.
Hoshino
T
T
Institute of Applied Biochemistry, University of Tsukuba, Ibaraki, Japan.
Fujii
R
R
Nakahara
T
T
D000595:Amino Acid Sequence; D001483:Base Sequence; D002338:Carotenoids / Q000096:biosynthesis / Q000235:genetics*; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D016963:Thermus thermophilus / Q000235:genetics* / Q000378:metabolism
D004269:DNA, Bacterial; D002338:Carotenoids