Tonon, T., Sayanova, O., Michaelson, L.V., Qing, R., Harvey, D., Larson, T.R., Li, Y., Napier, J.A. and Graham, I.A. (2005) Fatty acid desaturases from the microalga Thalassiosira pseudonana. FEBS Journal, 272 (13). pp. 3401-3412. ISSN 1742-464XFull text not available from this repository.
Analysis of a draft nuclear genome sequence of the diatom Thalassiosira pseudonana revealed the presence of 11 open reading frames showing significant similarity to functionally characterized fatty acid front-end desaturases. The corresponding genes occupy discrete chromosomal locations as determined by comparison with the recently published genome sequence. Phylogenetic analysis showed that two of the T. pseudonana desaturase (Tpdes) sequences grouped with proteobacterial desaturases that lack a fused cytochrome b5 domain. Among the nine remaining gene sequences, temporal expression analysis revealed that seven were expressed in T. pseudonana cells. One of these, TpdesN, was previously characterized as encoding a Δ11-desaturase active on palmitic acid. From the six remaining putative desaturase genes, we report here that three, TpdesI, TpdesO and TpdesK, respectively encode Δ6-, Δ5- and Δ4-desaturases involved in production of the health beneficial polyunsaturated fatty acid DHA (docosahexaenoic acid). Furthermore, we show that one of the remaining genes, TpdesB, encodes a Δ8-sphingolipid desaturase with strong preference for dihydroxylated substrates.
|Copyright, Publisher and Additional Information:||Open access copy available from the journal web site.|
|Keywords:||desaturases, long chain polyunsaturated fatty acids, sphingolipids, Thalassiosira pseudonana, yeast expression|
|Institution:||The University of York|
|Academic Units:||The University of York > Biology (York)|
|Depositing User:||Open Access From Journal|
|Date Deposited:||23 Dec 2008 11:16|
|Last Modified:||23 Dec 2008 11:16|