Efficient expression of truncated recombinant cadmium-metallothionein gene of a ciliate, Tetrahymena tropicalis lahorensis in Escherichia coli.

Truncated recombinant metallothionein GST-fusion protein has been successfully expressed in Escherichia coli. The previously identified novel Cd-inducible metallothionein (TMCd1) gene from the locally isolated ciliate, Tetrahymena tropicalis lahorensis, was inserted into a pET-41a vector, in frame with a sequence encoding an N-terminal glutathione-S-transferase (GST) tail. Truncated recombinant GST fusion protein has been purified by affinity column chromatography using glutathione sepharose.

A synthetic cadmium metallothionein gene (PMCd1syn) of Paramecium species: expression, purification and characteristics of metallothionein protein.

Metallothioneins (MTs) are metal binding proteins that are rich in cysteine residues constituting 10-30 % of the total protein, and in which the thiol groups bind to the metal ions. The increasing amount of metal ions in the medium have shown increased production of MTs by different organisms such as bacteria, protozoa and mammals like humans. PMCd1 is the first gene ever discovered in Paramecium, a ciliated protozoan, that could produce this MT in response to cadmium.

Identification and cloning of first cadmium metallothionein like gene from locally isolated ciliate, Paramecium sp.

First cadmium metallothionein like gene PMCd1 of a ciliate, Paramecium sp., isolated from industrial wastewater has been cloned and sequenced. PMCd1 is an intronless gene, encoding 612 nucleotides, with TAA coding for glutamine.

Identification, cloning and sequencing of a novel stress inducible metallothionein gene from locally isolated Tetrahymena tropicalis lahorensis.

A novel cadmium inducible metallothionein (TMCd1) gene has been identified and sequenced from the locally isolated ciliate, Tetrahymena tropicalis lahorensis from industrial effluents. The TMCd1 gene encodes 471 nucleotides, with TGA as the stop codon and TAA coding for glutamine. This new gene is quite different from the previously reported MT genes in Tetrahymena pyriformis and Tetrahymena pigmentosa.