Bioinformatics analysis of the HMGR of rate-limiting enzyme in the mevalonate pathway from Yarrowia lipolytica was carried out. The activity domain (tHMG, amino acids 441~875) was cloned and co-expressed with the labeled molecule GFP. Bioinformatics analysis showed that the HMGR gene can encode a hydrophobic labile protein containing 999 amino acids. The first 500 amino acid peptide chains contain more transmembrane region, the molecular weight was 254.93 kDa and theoretical pI was 4.77. The active domain contains 506 amino acids with a molecular weight of 127.74 kDa and a theoretical isoelectric point of 4.93, which contains the non-transmembrane region. The secondary structures of the two proteins (HMGR and tHMG) are mainly α-helix and random coil, and their tertiary structures are in the state of homologous tetramer. The yeast cells expressing tHMG-GFP were observed at the excitation wavelength of 488 nm, and the green fluorescence was found. After overexpression of catalytic domain (tHMG), the enzyme activity was 1.14 U/mg, which was 62.7% higher than that of the control. The results showed that the catalytic domain of HMGR could be expressed independently and it can increase the enzyme activity of HMGR in the cells.

Yarrowia lipolytica; mevalonate pathway; 3-hydroxy-3-methylglutaryl-CoA reductase; bioinformatics analysis; fusion expression