부산대학교 도서관

In this study, a pyruvate carboxylase gene ( PYC ) from a marine fungus Penicillium viticola 152 isolated from marine algae was cloned and characterized by using Genome Walking method. An open reading frame (ORF) of The PYC gene (accession number: KM593097 ) had 3582 bp encoding 1193 amino acid protein (isoelectric point: 5.01) with a calculated molecular weight of 131.2757 kDa. A putative promoter (intronless) of the gene was located at − 666 bp and contained a TATA box, several CAAT boxes, the 5′-SYGGRG-3′ and a 5′-HGATAR-3′ sequences. A consensus polyadenylation site (AATAAA) was also observed at + 10 bp downstream of the ORF. The protein deduced from the PYC gene had no signal peptide, was a homotetramer (4), and had the four functional domains. Furthermore, PYC protein also had three potential N-linked glycosylation sites, among them, -N-S-T-I- at 36 amino acid, -N-G-T-V- at 237 amino acid, and -N-G-S-S- at 517 amino acid were the most possible N -glycosylation sites. After expression of the PYC gene of P . viticola 152 in medium supplemented with CSL and biotin, it was found that the specific pyruvate carboxylase activity in MA production medium supplemented with CSL was much higher (0.5 U/mg) than in MA medium supplemented with biotin (0.3 U/mg), suggesting that optimal concentration of CSL is required for increased expression of the PYC gene, which is responsible for high level production of malic acid in P . viticola 152 strain. [ABSTRACT FROM AUTHOR]