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Rhizomucor miehei triglyceride lipase is synthesized as a precursor
Author(s) -
Boel Esper,
HugeJensen Birgitte,
Christensen Mogens,
Thim Lars,
Fiil Niels P.
Publication year - 1988
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02535672
Subject(s) - rhizomucor miehei , biochemistry , lipase , biology , peptide sequence , triacylglycerol lipase , serine , amino acid , complementary dna , signal peptide , enzyme , triglyceride lipase , gene
A Rhizomucor miehie cDNA library constructed in Escherichia coli was screened with synthetic oligonucleotides designed from knowledge of a partial amino acid sequence of the secreted triglyceride lipase (triacyl‐glycerol acylhydrolase EC 3.1.1.3) from this fungus. Lipase‐specific recombinants were isolated and their insert sequenced. Unlike characterized bacterial and mammalian triglyceride lipases, the fungal enzyme is synthesized as a precursor, including a 70 amino acid residue propeptide between the 24 amino acid residues of the signal peptide and the 269 residues of the mature enzyme. The precursor processing mechanism, which involves cleavage between a methionine and a serine residue, is unknown. By sequence comparison with other lipases, a serine residue involved in substrate binding was identified in the fungal lipase. The sequence around this residue is well‐conserved among characterized lipases. Conservation of an intron in an isolated cDNA recombinant and immunoprecipitation of in vitro synthesized R. miehei translation products indicates that the expression of the lipase gene might involve inefficient mRNA splicing.