PARTIAL CDNA SEQUENCE OF A METALLOTHIONEIN-LIKE PROTEIN WITH NEW FEATURES FROM THE BIVALVE MACOMA-BALTHICA

The marine bivalve Macoma balthica was experimentally treated with sub lethal doses of Cd2+. The mantel RNA was reverse-transcribed and PCR-a mplified using degenerate primers. RT-PCR amplification revealed a spe cific band of 300 bp. Amino acid composition deduced from this sequenc e fell into the specific feature mainly concerning a high level of cys teine in metallothionein. However, due to a different dispersion of cy steine residues along the sequence, no significant homology could be n oted from the comparison of the amino acid sequence with those of know n metallothioneins. Consequently, this M. balthica protein might belon g to class II metallothioneins.