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. However, it shows 78% homology with four different Cd-MT genes reported from Tetrahymena thermophila. A TATA box is located in the 5' flanking region at nucleotide 34-38 upstream region of ATG. The TMCd1 gene is intronless like many other genes isolated from Tetrahymena species. The amino acids sequence of TMCd1 has a special feature of three CCCX(6)CCX(6)CCCX(6)CC and two CCX(6)CXCX(2)CXCC intragenic tandem repeats with a conserved structural pattern of cysteine. The translated protein of TMCd1 contains 30.12% cysteine residues, which is a characteristic of a typical Tetrahymena Cd inducible MT genes. On the basis of 78% homology of nucleotide sequence of genomic DNA and its cDNA, TMCd1 has been considered as a new gene being reported from Tetrahymena tropicalis from this part of the world.
Shuja
Rukhsana N
RN
School of Biological Sciences, University of the Punjab, New Campus, Lahore 54590, Pakistan. rukhshuja@yahoo.com
Shakoori
Abdul Rauf
AR
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary; D008668:Metallothionein / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012091:Repetitive Sequences, Nucleic Acid; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013768:Tetrahymena / Q000235:genetics* / Q000254:growth & development
D018076:DNA, Complementary; D008668:Metallothionein