Genomic Cloning and Characterization of a FIP-gsi Gene Encoding a Fungal Immunomodulatory Protein from Ganoderma sinense Zhao et al. (Aphyllophoromycetideae)

A genomic DNA sequence encoding fungal immunomodulatory protein (FIP), the FIP-gsi gene, was isolated from Ganoderma sinense (Ganodermataceae, Basidiomycetes) using genomic walker technology. Analysis of 1072-bp segments revealed that the gene contained a 501-bp 5'-flanking region, a 333-bp open read frame (ORF), and a 238-bp 3'-flanking region. There is one putative TATA box and one possible CAAT box lieing in the 5'-flanking region. The ORF encodes a 12.4-kDa precursor polypeptide. One intron was found in the 5'-flanking region. The deduced amino acid sequence of FIP-gsi shares high similarity with other FIPs, for example, G. lucidum (FIP-glu), G. japonicum (FIP-gja), G. tsugae (FIP-gts), Flammulina velutipes (FIP-fve), and Volvariella volvacea (FIP-vvo), which were found to be 99%, 86%, 86%, 61%, and 56% identical, respectively. The cloning of the genomic DNA sequence is an important foundation for further study of its structure, expression, and regulatory mechanisms.