Molecular cloning of a cDNA encoding alpha-glucosidase in the digestive gland of the shrimp, Litopenaeus vannamei

The complete sequence of the 3-kb cDNA and the 5' genomic structure are reported for the gene encoding the shrimp alpha-glucosidase. Alpha-glucosidase cDNA was isolated from a shrimp digestive gland cDNA library. The 2830-base pair cDNA contains an open reading frame that encodes 919 amino acids. The shrimp alpha-glucosidase cDNA shows a high level of identity with that of the human sucrase-isomaltase, human maltase-glucoamylase, and human acid lysosomal alpha-glucosidase, indicating that the protein shares the same structural domains. The similarities among these proteins are found as clusters and characterize the glycosyl hydrolase family 31. To our knowledge, this is the first report to describe a satellite sequence in the 5' genomic structure before the TATA box in an invertebrate sequence.