Bacterial desaturases

Over-expression of bacterial phytoene synthase led to only modest increases in pigment accumulation (except in the case of chloroplast-contaiifing tissues). Attention turned to CrtI, one gene that might control flux through the entire four desaturation steps from phytoene to lycopene (discussed in Section 5.3.2.4). Only a modest increase in carotenoid content in tomatoes and a variety of changes in carotenoid composition including more P-carotene, accompanied by an overall decrease in total carotenoid content (no lycopene increase), resulted when CrtI was over-expressed under control of CaMV 35S. Apparently, the bacterial desaturase... 

Al-Babih, S., Hoa, T.T.C., and Schaub, R, Exploring the potential of the bacterial carotene desaturase CrtI to increase the beta-carotene content in Golden Rice, J. Exp. Bot. 57, 1007, 2006. 

A group of related bacterial enzymes hydroxylate alkanes,507 toluene,508 phenol,509 and other substrates.5093 Eukaryotic fatty acid desaturases (Fig. 16-20B) belong to the same family.508 Some bacteria use cytochrome P450 or other oxygenase to add an oxygen atom to an alkene to form an epoxide. For example, propylene... 

Strittmatter P., Thiede M. A., Hackett C. S. and Ozols J. (1988) Bacterial synthesis of active rat stearoyl-CoA desaturase lacking the 26-residue amino-terminal amino acid sequence. J. Biol. Chem. 263, 2532-2535. 

Aguilar, P.S., Cronan, J.E., Jr. and de Mendoza, D. A Bacillus subtilis gene induced by cold shock encodes a membrane phospholipid desaturase. J Bacterial, 180 (1998) 2194-2200. 

Aguilar, P.S., Lopez, P. and de Mendoza, D. Transcriptional control of the low-temperature-inducible des gene, encoding the deltaS desaturase of Bacillus subtilis. J Bacterial, 181 (1999) 7028-7033. 

Altabe, S.G., Aguilar, P., Caballero, G.M. and de Mendoza, D. The Bacillus subtilis acyl lipid desaturase is a deltas desaturase. J Bacterial, 185 (2003) 3228-3231. 

Bossie, M.A. and Martin, C.E. Nutritional regulation of yeast delta-9 fatty acid desaturase activity. J Bacterial, 171 (1989) 6409-6413. 

Carotene desaturase catalyzes the final two desaturation steps to lycopene by introducing two double bonds at positions 7,8 of -carotene and 7, 8 of neurosporene. From cyanobacteria, two structurally unrelated genes for -carotene desaturase have been cloned. One crtQ (formerly called zds) from Anabaena is related to the bacterial crtI gene, whereas the second crtQb (also called crtQ-2) from Synechocystis is quite similar to crtP. 

Tsuchiya T, Takaichi S, Misawa N, Maoka T, Miyashita H, Mimuro M (2005) The cyanobacterium Gloeobacter violaceus PCC 7421 uses bacterial-type phytoene desaturase in carotenoid biosynthesis. FEES Lett 579 2125-2129... 

Harada J, Nagashima KVP, Takaichi S, Misawa N, Matsuura K, Shimada K (2001) Phytoene desaturase, CrtI, of the purple photosynthetic bacterium, Rubrivivax gelatinosus, produces both neurosporene and lycopene. Plant Cell Physiol 42 1112-1118 Francis GW, Liaaen-Jensen S (1970) Bacterial carotenoids XXXIII. Carotenoids of thiorhodaceae 9. The structures of the carotenoids of the rhodopinal series. Acta Chem Scand 24 2705-2712... 

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