Biosynthesis genes

Although carotenogenesis in plants takes place in plastids, all of the carotenoid biosynthesis genes are nuclear encoded and their polypeptide products are imported into the plastids. Therefore, they contain a N-terminal transit peptide sequence. For example, the size of the transit peptide of PSY from ripe tomato fruit is approximately 9 kDa, corresponding to about 80 amino acid residues (Misawa et al, 1994). 

GiuLiANO G (1996) Regulation of a carotenoid biosynthesis gene promoter during plant development , Plant J, 9, 505-12. 

LINDEN H, MISAWA N, SAITO T and SANDMANN G (1994) A uovel caroteuoid biosynthesis gene coding for -carotene desaturase functional expression, sequence and phylogenetic origin . Plant Mol Biol, 24, 369-79. 

Linden, H., Vioque, A., and Sandmann, G., Isolation of a carotenoid biosynthesis gene coding for z-carotene dasaturase from Anabaena PCC 7120 by heterologous complementation, FFMS Microbiol. Lett. 106, 99, 1993. 

M. G. Bangera and L. S. Thomashow, Identification and characterization of a novel polyketide locus containing 2,4-diacetylphloroglucinol biosynthesis genes from Pseudomonas fluorescens Q2-87. J. Hacteriol. (1997). 

Nakagawa, M. and N. Misawa. 1991. Analysis of carotenoid glycosides produced in gram-negative bacteria by introduction of the Erwinia uredovora carotenoid biosynthesis genes. Agric. Biol. Chem. 55 2147-2148. 

Aidoo, K.A., Wong, A., Alexander, D.C. et al. (1994) Cloning, sequencing and disruption of a gene from Streptomyces clavuligerus involved in clavulanic acid biosynthesis. Gene, 147, 41—46. 

The availability of a variety of Gtfs and sugar biosynthesis genes provides the basis for a general strategy to produce glycosylated molecules in vivo [85]. For example, a Gtf from... 

There are several good reasons to express PHA biosynthesis genes in a different organism, and they are summarized in Tables 3 and 4 ... 

Table 3. Heterologous , expression of PHA biosynthesis genes and related genes ...

Genetic engineering of PHA synthase proteins in E. coli in combination with a suitable viable-colony staining method for the screening of PHA content [143] will make many methodological tools applicable to PHA biosynthesis genes and proteins and will allow studies on structure to function relation-... 

Much effort has been made to use recombinant strains of E. coli, which expressed the PHA biosynthesis genes from R. eutropha, or other combinations of a suitable host organism and foreign PHA biosynthesis genes for high cell density cultivation and production of bulk amounts of PHAs. The interested reader is referred to a different chapter of this book [13] and the references cited therein in which these systems are described in detail. 

Keywords. Polyhydroxyalkanoates, PHA biosynthesis genes, Recombinant bacteria, Fermentation... 

A mutant E. coli strain LS5218 (fadR atoC) was employed for the synthesis of P(3HB-co-3HV) copolymer since this mutant strain constitutively expresses the enzymes involved in the transport and utilization of short chain fatty acids [58, 59]. P(3HB-co-3HV) could be synthesized by a recombinant E. coli strain LS5218 harboring the R. eutropha PHA biosynthesis genes when propionic acid or valeric acid was added as a cosubstrate [58,60]. The P(3HB-co-3HV) copolymer consisting of up to 40 mol% of 3HV could be produced. An alternative method that allowed synthesis of P(3HB-co-3HV) using propionic acid or valeric... 

Two different PHA biosynthesis gene loci were recently cloned [95]. The PHA negative mutant of R. eutropha harboring the Pseudomonas sp. PHA biosynthesis locus produced PHA consisting of 3HB, 3HHx, 3HO, and 3-hydroxy-decanoate (3HD), 3-hydroxydodecanoate (3HDD) with the PHA content of up to 14 wt % of CDW. 

---