Characterization and heterospecific expression of cDNA clones of genes in the maize GSH S-transferase multigene family.
We have isolated from a constructed lambda gt11 expression library two classes of cDNA clones encoding the entire sequence of the maize GSH S-transferases GST I and GST III. Expression of a full-length GST I cDNA in E. coli resulted in the synthesis of enzymatically active maize GST I that is immunologically indistinguishable from the native GST I. Another GST I cDNA with a truncated N-terminal sequence is also active in heterospecific expression. Our GST III cDNA sequence differs from the version reported by Moore et al. [Moore, R. E., Davies, M. S., O'Connell, K. M., Harding, E. I., Wiegand, R. C., and Tiemeier, D. C. (1986) Nucleic Acids Res. 14:7227-7235] in eight reading frame shifts which result in partial amino acid sequence conservation with the rat GSH S-transferase sequences. The GST I and GST III sequences share approximately 45% amino acid sequence homology. Both the GST I and the GST III mRNAs contain different repeating motifs in front of the initiation codon ATG. Multiple poly(A) addition sites have been identified for these two classes of maize GSH S-transferase messages. Genomic Southern blotting results suggest that both GST I and GST III are present in single or low copies in the maize (GT112 RfRf) genome.
Grove
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Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802.
Zarlengo
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Timmerman
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D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D005786:Gene Expression Regulation; D005796:Genes; D005982:Glutathione Transferase / Q000235:genetics*; D007158:Immunologic Techniques; D008969:Molecular Sequence Data; D005810:Multigene Family; D013045:Species Specificity; D003313:Zea mays / Q000235:genetics*
D004247:DNA; D005982:Glutathione Transferase