CLONING AND NUCLEOTIDE-SEQUENCE OF CDNA-ENCODING A LIPASE FROM FUSARIUM-HETEROSPORUM

Fusarium heterosporum produces a solvent-tolerant lipase. A 1.3-kbp lipase cDNA was isolated from the cDNA library by colony hybridization with an oligonucleotide probe corresponding to the N-terminal amino acid sequence. Nucleotide sequence analysis showed an open reading frame of 999 bp, and the deduced amino acid sequence contained the N-terminal sequence determined by Edman degradation and the consensus pentapeptide (-Gly-X-Ser-X-Gly-), which is conserved in lipase, esterase, and serine protease. The mature lipase consisted of 301 amino acid residues with a molecular mass of 32.7 kDa, preceded by the putative signal peptide or preprosequence. The enzyme was homologous to lipases from Humicola lanuginosa (39% homology), Rhizomucor miehei (32%), Rhizopus delemar (32%), and Rhizopus niveus (32%), and to mono- and diacylglycerol lipase from Penicillium camembertii (38%). Comparison of this lipase with these homologous enzymes suggested that the catalytic triad was composed of Ser144, Asp198, and His256, and that the oxyanion hole was formed with Ser 82.