扩展青霉PF898碱性脂肪酶cDNA的克隆及序列分析

扩展青霉 (Penicilliumexpansum)PF898可产生一种具有工业价值的碱性脂肪酶 (PEL) .在测定了其N端 12个氨基酸残基序列的基础上 ,通过RT PCR、5′RACE、基因克隆及序列测定 ,获得了PEL完整的cDNA序列 (GenBank登录号为AF2 84 0 6 4 ) .cDNA全长 10 5 0bp ,包括PEL编码区、3′非翻译区和部分 5′非翻译区基因的序列 .编码区cDNA由 85 5个碱基组成 ,编码 1个由 2 85个氨基酸残基组成的酶蛋白 ,其信号肽及前肽部分由 2 7个氨基酸残基组成 ,成熟肽部分由 2 5 8个氨基酸残基组成 .根据氨基酸组成推导该脂肪酶蛋白的分子量为 2 7 3kD .该脂肪酶的氨基酸序列 130～ 134位上有各类脂肪酶中普遍存在的G X S X G保守序列

Cloning and Sequence Analysis of cDNA Encoding Alkaline Lipase from Penicillium expansum PF898

Penicillium expansum PF898 produces an alkaline lipase (PEL) with industrial value. A 5′primer was designed according to the first 12 amino acid residues of N terminal measured.The full length cDNA of 1 050 bp was amplified from total RNA of the fungus by RT PCR and 5′RACE. Analysis of the nucleotide sequence indicated that the amplified cDNA (GenBank accession number AF284064) contained a complete open reading frame encoding a protein of 285 amino acid residues including presumptive signal sequence or prepro sequence composed of 27 amino acid residues and a mature peptide composed of 258 amino acid residues. The sequence G X S X G highly preserved among lipases was found at position 130—134 in amino acid sequence of PEL. The molecular weight of mature peptide is 27 3 kD.