User:Malleman88
Hentriacontanonaene
[edit](3Z,6Z,9Z,12Z,15Z,19Z,22Z,25Z,28Z)-hentriaconta-3,6,9,12,15,19,22,25,28-nonaene) is a long chain polyunsaturated hydrocarbon produced by numerous gamma-proteobacteria primarily from the marine environment. Hentriacontanonaene was originally isolated from bacterial isolates from Antarctic sea ice cores [1] . All isolated bacteria that produced hentriacontanonaene also produced the polyunsaturated fatty acids eicosapentaenoic (EPA) and docosahexaenoic (DHA) acid[1][2] . Given its polyunsaturated nature it has been proposed that this molecule is produced as part of a response to maintain optimal membrane fluidity[1] [3].
Biosynthesis
[edit]The biosynthesis of this compound was initially identified by its similarity to other known pathways found in bacteria that produce similar long chain hydrocarbons[4]. Production of monounsaturated and tri-unsaturated long chain hydrocarbons in various microbial lineages has been attributed to the oleABCD gene cluster[3]. In this pathway two acyl-CoA or acyl-ACP are condensed using a non-decarboxylative Claisen condensation to yield a β-keto-thioester[5]. Hydrolysis from the enzyme is followed by reduction of the β-keto group to an alcohol catalyzed by an NADPH dependent reductase OleD[6]. The remaining steps include decarboxylation and dehydration, which might be combined as a single decarboxylation elimination step[6]. The exact roles of OleB and OleC in this pathway are unknown, however deletion of oleC yielded a strain that produced a mono-ketone product without the completed olefin[3].
The overall unsaturation of the compound is determined by the acyl precursors and it has been hypothesized that condensation of two 16:4(n-3) acyl chains by OleABCD yields hentriacontanonaene [3][4][2]. A polyketide-like pathway responsible for the production of eicosapentaenoic acid provides the polyunsaturated precursor for hentriacontanonaene[3].
Footnotes
[edit]- ^ a b c Nichols, David S.; Nichols, Peter D.; McMeekin, Tom A. (1995). "A new n-C31:9polyene hydrocarbon from Antarctic bacteria". FEMS Microbiology Letters. 125 (2–3): 281–285. doi:10.1111/j.1574-6968.1995.tb07369.x. ISSN 0378-1097.
- ^ a b Sugihara, Shinji; Hori, Ryuji; Nakanowatari, Hitomi; Takada, Yasuhiro; Yumoto, Isao; Morita, Naoki; Yano, Yutaka; Watanabe, Kazuo; Okuyama, Hidetoshi (2009). "Possible Biosynthetic Pathways for all cis-3,6,9,12,15,19,22,25,28-Hentriacontanonaene in Bacteria". Lipids. 45 (2): 167–177. doi:10.1007/s11745-009-3380-9. ISSN 0024-4201.
- ^ a b c d e Sukovich, D. J.; Seffernick, J. L.; Richman, J. E.; Hunt, K. A.; Gralnick, J. A.; Wackett, L. P. (2010). "Structure, Function, and Insights into the Biosynthesis of a Head-to-Head Hydrocarbon in Shewanella oneidensis Strain MR-1". Applied and Environmental Microbiology. 76 (12): 3842–3849. doi:10.1128/AEM.00433-10. ISSN 0099-2240.
- ^ a b Beller, H. R.; Goh, E.-B.; Keasling, J. D. (2009). "Genes Involved in Long-Chain Alkene Biosynthesis in Micrococcus luteus". Applied and Environmental Microbiology. 76 (4): 1212–1223. doi:10.1128/AEM.02312-09. ISSN 0099-2240.
- ^ Frias, J. A.; Richman, J. E.; Erickson, J. S.; Wackett, L. P. (2011). "Purification and Characterization of OleA from Xanthomonas campestris and Demonstration of a Non-decarboxylative Claisen Condensation Reaction". Journal of Biological Chemistry. 286 (13): 10930–10938. doi:10.1074/jbc.M110.216127. ISSN 0021-9258.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ a b Bonnett, Shilah A.; Papireddy, Kancharla; Higgins, Samuel; del Cardayre, Stephen; Reynolds, Kevin A. (2011). "Functional Characterization of an NADPH Dependent 2-Alkyl-3-ketoalkanoic Acid Reductase Involved in Olefin Biosynthesis inStenotrophomonas maltophilia". Biochemistry. 50 (44): 9633–9640. doi:10.1021/bi201096w. ISSN 0006-2960.