Rna-dependent dna polymerase from geobacillus stearothermophilus

Abstract

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.