文蛤MmASS基因克隆及生物信息学分析.

In this study, the complete cDNA sequence of argininosuccinate synthetase was cloned in the saltwater clam Meretrix meretrix using the rapid amplification of cDNA ends (RACE) approach. The complete MmASS cDNA measures 1588 bp in length with an open reading frame encoding 415 amino acids. The molecular weight of MmASS was 46.81 kD and the theoretical isoelectric point was 5.51. The deduced MmASS protein comprises six conserved sequences, containing the substrate-binding residues for ATP, aspartate and citrulline. The results of the multiple amino acid alignment and the phylogenetic analysis showed that MmASS exhibited high amino acid sequence identity with other species. MmASS also had a close phylogenetic relationship with Sinonovacula constricta. Overall, similar functions might exist in M. meretrix and other species. Predicted subcellular localization suggested that MmASS is a cytosolic enzyme. The expression levels of MmASS were distributed in all of the examined tissues. MmASS was most highly expressed in the gill (P<0.05), followed by the hepatopancreas. These results indicated that MmASS was involved in various physiological activities of different tissues and may play an important role in the immune mechanisms. [ABSTRACT FROM AUTHOR]