RNA-DEPENDENT DNA POLYMERASE FROM GEOBACILLUS STEAROTHERMOPHILUS
The invention provides an isolated polynucleotide sequence from the genome of Bacillus stearothermophilus ( Geobacillus stearothermophilus ) and an amino acid sequence encoded by the polynucleotide sequence, the corresponding amino acid sequence comprising a novel enzyme, Tirt (thermostable intron reverse transcriptase), having reverse transcriptase activity and retaining that activity at temperatures of up to about 75° C.
1 . A purified or isolated polynucleotide comprising a nucleic acid selected from the group consisting of:
a) SEQ ID NO:1;
b) a nucleic acid encoding the amino acid sequence of SEQ ID NO: 2; and
c) a nucleic acid which hybridizes with the nucleic acid of b) under stringent conditions and encodes a polypeptide having a similar reverse transcriptase activity to that of the polypeptide comprising SEQ ID NO:2.
2 . A vector comprising the polynucleotide of claim 1 .
3 . A host cell comprising the vector of claim 2 .
4 . A method of producing a reverse transcriptase, the method comprising:
a) introducing the vector of claim 2 into an expression system and
b) expressing the polypeptide product encoded by the polynucleotide of the vector.
5 . The method of claim 4 wherein the expression system is a host cell.
6 . The method of claim 4 wherein the expression system is a cell-free expression system.
7 . A method of producing a reverse transcriptase, the method comprising:
a) culturing a host cell comprising the vector of claim 6 ;
b) expressing a protein encoded by the polynucleotide; and
c) isolating the protein from the host cell.
8 . The method of claim 7 , wherein the host cell is E. coli.