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Comparative analysis of fatty acid desaturases in cyanobacterial genomes.

Chi X, Yang Q, Zhao F, Qin S, Yang Y, Shen J, Lin H - Comp. Funct. Genomics (2008)

Bottom Line: The pathway of acyl-lipid desaturation for unicellular marine cyanobacteria Synechococcus and Prochlorococcus differs from that of other cyanobacteria, indicating different phylogenetic histories of the two genera from other cyanobacteria isolated from freshwater, soil, or symbiont.Three thermophilic unicellular strains, Thermosynechococcus elongatus BP-1 and two Synechococcus Yellowstone species, lack highly unsaturated fatty acids in lipids and contain only one Delta9 desaturase in contrast with mesophilic strains, which is probably due to their thermic habitats.Thus, the amounts and types of fatty acid desaturases are various among different cyanobacterial species, which may result from the adaption to environments in evolution.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.

ABSTRACT
Fatty acid desaturases are enzymes that introduce double bonds into the hydrocarbon chains of fatty acids. The fatty acid desaturases from 37 cyanobacterial genomes were identified and classified based upon their conserved histidine-rich motifs and phylogenetic analysis, which help to determine the amounts and distributions of desaturases in cyanobacterial species. The filamentous or N(2)-fixing cyanobacteria usually possess more types of fatty acid desaturases than that of unicellular species. The pathway of acyl-lipid desaturation for unicellular marine cyanobacteria Synechococcus and Prochlorococcus differs from that of other cyanobacteria, indicating different phylogenetic histories of the two genera from other cyanobacteria isolated from freshwater, soil, or symbiont. Strain Gloeobacter violaceus PCC 7421 was isolated from calcareous rock and lacks thylakoid membranes. The types and amounts of desaturases of this strain are distinct to those of other cyanobacteria, reflecting the earliest divergence of it from the cyanobacterial line. Three thermophilic unicellular strains, Thermosynechococcus elongatus BP-1 and two Synechococcus Yellowstone species, lack highly unsaturated fatty acids in lipids and contain only one Delta9 desaturase in contrast with mesophilic strains, which is probably due to their thermic habitats. Thus, the amounts and types of fatty acid desaturases are various among different cyanobacterial species, which may result from the adaption to environments in evolution.

No MeSH data available.


Related in: MedlinePlus

Phylogenetic  tree of the sequenced cyanobacterial strains. A Neighbor-joining tree for 33 sequencedcyanobacteria constructed based on 16 S rRNA as was described inSection 2 and about 1300 positions were employed. To maximizethe number of sites available for analysis, three partial sequences from Synechococcus sp. RS9917 (170 bp), Synechococcus sp. RS9916 (865 bp), and Synechococcus sp. BL107 (296 bp) wereexcluded. Moreover, no 16 S rRNA sequence was foundin Cyanothece sp. CCY0110.
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fig1: Phylogenetic tree of the sequenced cyanobacterial strains. A Neighbor-joining tree for 33 sequencedcyanobacteria constructed based on 16 S rRNA as was described inSection 2 and about 1300 positions were employed. To maximizethe number of sites available for analysis, three partial sequences from Synechococcus sp. RS9917 (170 bp), Synechococcus sp. RS9916 (865 bp), and Synechococcus sp. BL107 (296 bp) wereexcluded. Moreover, no 16 S rRNA sequence was foundin Cyanothece sp. CCY0110.

Mentions: Theentire genome sequence of a unicellular cyanobacterium Synechocystis sp. strain PCC 6803 was first described in 1996 [16].To date, 37 cyanobacterial genomes have been sequenced (Figure 1). Thesegenomes are those of the filamentous nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120, the thermophilicstrain Thermosynechococcus elongatus BP-1, the thylakoid-free strain Gloeobacterviolaceus PCC 7421, the marine cyanobacterium Synechococcus sp. strain WH8102, the Prochlorococcus marinus strains SS120, MED4, MIT 9313, Synechococcus sp. CC9311, and others.These genome-sequencing projects undoubtedly bring a great convenience toobtain a comprehensive dataset of genes involvedin unsaturated fatty acid biosynthesis in cyanobacteria. Inthis work, we identified all the putative fatty acid desaturases usingbioinformatic tools and presented a genomic comparison of the fatty aciddesaturases from 37 cyanobacterial genomes. The identification ofnovel desaturases and the reconstruction of the pathways for unsaturated fattyacid biosynthesis in cyanobacteria will guide the experimental analysis and provide cluesin study of the relationship between the unsaturation level ofmembrane lipids and environmental adaptation in higher plants.


Comparative analysis of fatty acid desaturases in cyanobacterial genomes.

Chi X, Yang Q, Zhao F, Qin S, Yang Y, Shen J, Lin H - Comp. Funct. Genomics (2008)

Phylogenetic  tree of the sequenced cyanobacterial strains. A Neighbor-joining tree for 33 sequencedcyanobacteria constructed based on 16 S rRNA as was described inSection 2 and about 1300 positions were employed. To maximizethe number of sites available for analysis, three partial sequences from Synechococcus sp. RS9917 (170 bp), Synechococcus sp. RS9916 (865 bp), and Synechococcus sp. BL107 (296 bp) wereexcluded. Moreover, no 16 S rRNA sequence was foundin Cyanothece sp. CCY0110.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2593844&req=5

fig1: Phylogenetic tree of the sequenced cyanobacterial strains. A Neighbor-joining tree for 33 sequencedcyanobacteria constructed based on 16 S rRNA as was described inSection 2 and about 1300 positions were employed. To maximizethe number of sites available for analysis, three partial sequences from Synechococcus sp. RS9917 (170 bp), Synechococcus sp. RS9916 (865 bp), and Synechococcus sp. BL107 (296 bp) wereexcluded. Moreover, no 16 S rRNA sequence was foundin Cyanothece sp. CCY0110.
Mentions: Theentire genome sequence of a unicellular cyanobacterium Synechocystis sp. strain PCC 6803 was first described in 1996 [16].To date, 37 cyanobacterial genomes have been sequenced (Figure 1). Thesegenomes are those of the filamentous nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120, the thermophilicstrain Thermosynechococcus elongatus BP-1, the thylakoid-free strain Gloeobacterviolaceus PCC 7421, the marine cyanobacterium Synechococcus sp. strain WH8102, the Prochlorococcus marinus strains SS120, MED4, MIT 9313, Synechococcus sp. CC9311, and others.These genome-sequencing projects undoubtedly bring a great convenience toobtain a comprehensive dataset of genes involvedin unsaturated fatty acid biosynthesis in cyanobacteria. Inthis work, we identified all the putative fatty acid desaturases usingbioinformatic tools and presented a genomic comparison of the fatty aciddesaturases from 37 cyanobacterial genomes. The identification ofnovel desaturases and the reconstruction of the pathways for unsaturated fattyacid biosynthesis in cyanobacteria will guide the experimental analysis and provide cluesin study of the relationship between the unsaturation level ofmembrane lipids and environmental adaptation in higher plants.

Bottom Line: The pathway of acyl-lipid desaturation for unicellular marine cyanobacteria Synechococcus and Prochlorococcus differs from that of other cyanobacteria, indicating different phylogenetic histories of the two genera from other cyanobacteria isolated from freshwater, soil, or symbiont.Three thermophilic unicellular strains, Thermosynechococcus elongatus BP-1 and two Synechococcus Yellowstone species, lack highly unsaturated fatty acids in lipids and contain only one Delta9 desaturase in contrast with mesophilic strains, which is probably due to their thermic habitats.Thus, the amounts and types of fatty acid desaturases are various among different cyanobacterial species, which may result from the adaption to environments in evolution.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.

ABSTRACT
Fatty acid desaturases are enzymes that introduce double bonds into the hydrocarbon chains of fatty acids. The fatty acid desaturases from 37 cyanobacterial genomes were identified and classified based upon their conserved histidine-rich motifs and phylogenetic analysis, which help to determine the amounts and distributions of desaturases in cyanobacterial species. The filamentous or N(2)-fixing cyanobacteria usually possess more types of fatty acid desaturases than that of unicellular species. The pathway of acyl-lipid desaturation for unicellular marine cyanobacteria Synechococcus and Prochlorococcus differs from that of other cyanobacteria, indicating different phylogenetic histories of the two genera from other cyanobacteria isolated from freshwater, soil, or symbiont. Strain Gloeobacter violaceus PCC 7421 was isolated from calcareous rock and lacks thylakoid membranes. The types and amounts of desaturases of this strain are distinct to those of other cyanobacteria, reflecting the earliest divergence of it from the cyanobacterial line. Three thermophilic unicellular strains, Thermosynechococcus elongatus BP-1 and two Synechococcus Yellowstone species, lack highly unsaturated fatty acids in lipids and contain only one Delta9 desaturase in contrast with mesophilic strains, which is probably due to their thermic habitats. Thus, the amounts and types of fatty acid desaturases are various among different cyanobacterial species, which may result from the adaption to environments in evolution.

No MeSH data available.


Related in: MedlinePlus