Cloning and sequence analysis of putative type II fatty acid synthase genes from Arachis hypogaea L.
The cultivated peanut is a valuable source of dietary oil and ranks fifth among the world oil crops. Plant fatty acid biosynthesis is catalysed by type II fatty acid synthase (FAS) in plastids and mitochondria. By constructing a full-length cDNA library derived from immature peanut seeds and homology-based cloning, candidate genes of acyl carrier protein (ACP), malonyl-CoA:ACP transacylase, beta-ketoacyl-ACP synthase (I, II, III), beta-ketoacyl-ACP reductase, beta-hydroxyacyl-ACP dehydrase and enoyl-ACP reductase were isolated. Sequence alignments revealed that primary structures of type II FAS enzymes were highly conserved in higher plants and the catalytic residues were strictly conserved in Escherichia coli and higher plants. Homologue numbers of each type II FAS gene expressing in developing peanut seeds varied from 1 in KASII, KASIII and HD to 5 in ENR. The number of single-nucleotide polymorphisms (SNPs) was quite different in each gene. Peanut type II FAS genes were predicted to target plastids except ACP2 and ACP3. The results suggested that peanut may contain two type II FAS systems in plastids and mitochondria. The type II FAS enzymes in higher plants may have similar functions as those in E. coli.
Li
Meng-Jun
MJ
High-Tech Research Center, Shandong Academy of Agricultural Sciences, Key Laboratory for Genetic Improvement of Crop, Animal and Poultry of Shandong Province, Huanghuaihai, Ministry of Agriculture, Ji'nan 250100, China.
Li
Ai-Qin
AQ
Xia
Han
H
Zhao
Chuan-Zhi
CZ
Li
Chang-Sheng
CS
Wan
Shu-Bo
SB
Bi
Yu-Ping
YP
Wang
Xing-Jun
XJ
D000595:Amino Acid Sequence; D010367:Arachis / Q000201:enzymology* / Q000235:genetics*; D003001:Cloning, Molecular; D019295:Computational Biology / Q000379:methods; D018076:DNA, Complementary / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D064429:Fatty Acid Synthases / Q000737:chemistry* / Q000235:genetics*; D015723:Gene Library; D008928:Mitochondria / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D018087:Plastids / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D012313:RNA; D064429:Fatty Acid Synthases