Abstract
Mammalian metallothioneins (MTs) possess eight highly conserved lysine residues, including three in each of two metal binding domains. We used site-directed mutagenesis to replace these intradomain lysines in Chinese hamster ovary MT2 with glutamic acid and/or glutamine. These mutant MTs were expressed in a metal sensitive yeast host. One mutant which had all three lysines in the α-domain replaced by glutamates (K43,51,56E) exhibited a reduced ability, relative to native MT, to protect yeast transformants against otherwise toxic levels of cadmium. This triply substituted mutant also exhibited anomalous migration on a non-denaturing gel relative to wild type MT and other MT lysine mutants, suggesting that the intradomain lysines are important in maintaining the conformational integrity of MT.
Original language | English (US) |
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Pages (from-to) | 954-959 |
Number of pages | 6 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 202 |
Issue number | 2 |
DOIs | |
State | Published - Jul 29 1994 |
Externally published | Yes |
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology