A mu-class glutathione S-transferase from the marine shrimp Litopenaeus vannamei: Molecular cloning and active-site structural modeling

✍ Scribed by Carmen A. Contreras-Vergara; Citlalli Harris-Valle; Rogerio R. Sotelo-Mundo; Gloria Yepiz-Plascencia

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 318 KB
• Volume: 18
• Category: Article
• ISSN: 1095-6670
• DOI: 10.1002/jbt.20033

✦ Synopsis

Abstract

A cDNA clone coding for a mu‐class glutathione S‐transferase (GST) was isolated from a hepatopancreas cDNA library from the shrimp Litopenaeus vannamei. The deduced amino acid sequence (215 amino acids) has >50% identity to rodents and other mammals mu‐class GSTs. Using RT‐PCR, the shrimp GST transcript was detected in hepatopancreas, hemocytes, gills, and muscle, but not in pleopods. The shrimp GST sequence was computer modeled and found to fit the classical two‐domain GST structure. Domain I, containing the glutathione (GSH) binding site, is more conserved compared to the flexible C‐terminal domain II. Residue Q208 appears to be a key to substrate specificity by comparison with mammalian GST mutants. This position is commonly occupied by serine or threonine in mammalian mu‐class GSTs, and shrimp Q208 may affect the affinity to substrates like aminochrome or 1,3‐dimethyl‐2‐cyano‐1‐nitrosoguanidine. This is the first report of molecular cloning and structural modeling of a crustacean GST and provides new insights into the nature of the detoxification response on marine invertebrates. © 2004 Wiley Periodicals, Inc. J Biochem Mol Toxicol 18:245–252, 2004 Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20033