TY - JOUR
T1 - Sigma-class glutathione transferase from Xenopus laevis
T2 - Molecular cloning, expression, and site-directed mutagenesis
AU - Carletti, Erminia
AU - De Luca, Antonella
AU - Urbani, Andrea
AU - Sacchetta, Paolo
AU - Di Ilio, Carmine
PY - 2003/11/15
Y1 - 2003/11/15
N2 - The structural gene for glutathione transferase (XlGSTS1-1) in the amphibia Xenopus laevis has been cloned from an embryo library and its nucleotide sequence has been determined. Open reading frame analysis indicated that xlgsts1 gene encodes the smallest protein of sigma class GST so far identified as being composed of only 194 amino acid residues. The recombinant XlGSTS1-1 shows a narrow range of substrate specificity as well as a significantly lower 1-chloro-2,4-dinitrobenzene conjugation capacity than that of squid sigma class GST. To compare the structural and functional differences between the squid and amphibian enzymes, several site-specific mutations were introduced in XlGSTS1-1, i.e., Ser100Asn, Phe102Tyr, Trp143Leu, Phe146Leu, and Trp148Cys. The results obtained indicate that Trp143 and Trp148 are more important determinants for the structural stability of XlGSTS1-1 rather than for its substrate specificity.
AB - The structural gene for glutathione transferase (XlGSTS1-1) in the amphibia Xenopus laevis has been cloned from an embryo library and its nucleotide sequence has been determined. Open reading frame analysis indicated that xlgsts1 gene encodes the smallest protein of sigma class GST so far identified as being composed of only 194 amino acid residues. The recombinant XlGSTS1-1 shows a narrow range of substrate specificity as well as a significantly lower 1-chloro-2,4-dinitrobenzene conjugation capacity than that of squid sigma class GST. To compare the structural and functional differences between the squid and amphibian enzymes, several site-specific mutations were introduced in XlGSTS1-1, i.e., Ser100Asn, Phe102Tyr, Trp143Leu, Phe146Leu, and Trp148Cys. The results obtained indicate that Trp143 and Trp148 are more important determinants for the structural stability of XlGSTS1-1 rather than for its substrate specificity.
KW - Amphibian
KW - Site-directed mutagenesis
KW - Tryptophan residues
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U2 - 10.1016/j.abb.2003.08.024
DO - 10.1016/j.abb.2003.08.024
M3 - Article
C2 - 14592465
AN - SCOPUS:0142258007
SN - 0003-9861
VL - 419
SP - 214
EP - 221
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
IS - 2
ER -