Molecular cloning, characterization, and heterologous expression of an acetyl-CoA acetyl transferase gene from Sanghuangporus baumii

Acetyl-CoA C-acetyltransferase synthase gene (AACT) cDNA, DNA and promoter were cloned from Sanghuangporus baumii. The gene ORF (1260 bp) encoded 419 amino acids. The AACT DNA includes five exons (1–84 bp, 140–513 bp, 570–1027 bp, 1090–1282 bp, 1344–1494 bp) and four introns (85–139 bp, 514–569 bp, 1028–1089 bp, 1283–1343 bp). The molecular weight of AACT protein is 43.40 kDa, it is hydrophilic with a theoretical isoelectric point of 8.96. Furthermore, The region of the transcription start site is 1997–2047 bp of AACT promoter, and it contained promoter elements (TATA Boxs, CAAT Boxs, CAAT-box, ABRE, G-Boxs, Sp1, MSA-like, LTR). AACT recombinant protein (43.40 KDa + Tag protein 22.68 KDa) was subjected in SDS-PAGE. AACT the transcription levels of in different development stages were investigated. The expression of AACT in primordia (2.4-fold) and 15 d mycelia (2.3- fold) were significantly higher than 9 d mycelia (contral). The expression level of the AACT downstream genes and triterpenoids content were determined at different developmental stages. Triterpenoid content reached its peak on day 15(7.21 mg/g).