Cloning and characterization of squalene synthase (SQS) gene from Ganoderma lucidum.
This report provides the complete nucleotide sequences of the full-length cDNA encoding squalene synthase (SQS) and its genomic DNA sequence from a triterpene-producing fungus, Ganoderma lucidum. The cDNA of the squalene synthase (SQS) (GenBank Accession Number: DQ494674) was found to contain an open reading frame (ORF) of 1,404 bp encoding a 468-amino-acid polypeptide, whereas the SQS genomic DNA sequence (GenBank Accession Number: DQ494675) consisted of 1,984 bp and contained four exons and three introns. Only one gene copy was present in the G lucidum genome. The deduced amino acid sequence of Ganoderma lucidum squalene synthase (Gl-SQS) exhibited a high homology with other fungal squalene synthase genes and contained six conserved domains. A phylogenetic analysis revealed that G. lucidum SQS belonged to the fungi SQS group, and was more closely related to the SQS of U. maydis than to those of other fungi. A gene expression analysis showed that the expression level was relatively low in mycelia incubated for 12 days, increased after 14 to 20 days of incubation, and reached a relatively high level in the mushroom primordia. Functional complementation of Gl-SQS in a SQS-deficient strain of Saccharomyces cerevisiae confirmed that the cloned cDNA encoded a squalene synthase.
Zhao
Ming-Wen
MW
College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Nanjing 210095, Jiangsu, PR China. mwzhao@njau.edu.cn
Liang
Wan-Qi
WQ
Zhang
Da-Bing
DB
Wang
Nan
N
Wang
Chen-Guang
CG
Pan
Ying-Jie
YJ
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular / Q000379:methods; D018076:DNA, Complementary; D004271:DNA, Fungal / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics; D005091:Exons; D013186:Farnesyl-Diphosphate Farnesyltransferase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D018628:Gene Dosage; D015870:Gene Expression; D015723:Gene Library; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D007438:Introns; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D017434:Protein Structure, Tertiary; D020940:Reishi / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014170:Transformation, Genetic
D018076:DNA, Complementary; D004271:DNA, Fungal; D013186:Farnesyl-Diphosphate Farnesyltransferase