Bacillus stearothermophilus SSB protein and use thereof

Abstract

The present invention relates to an isolated DNA molecule from a thermophilic bacterium which encodes a DNA polymerase III-type enzyme subunit. Also encompassed by the present invention are host cells and expression system including the heterologous DNA molecule of the present invention, as well as isolated replication enzyme subunits encoded by such DNA molecules. Also disclosed is a method of producing a recombinant thermostable DNA polymerase III-type enzyme, or subunit thereof, from a thermophilic bacterium, which is carried out by transforming a host cell with at least one heterologous DNA molecule of the present invention under conditions suitable for expression of the DNA polymerase III-type enzyme, or subunit thereof, and then isolating the DNA polymerase III-type enzyme, or subunit thereof.

What is claimed:  
     
         1 . An isolated Bacillus single-strand binding protein: 
 (i) comprising the amino acid sequence of SEQ ID NO: 176; or    (ii) being encoded by a nucleic acid molecule hybridizing to the complement of SEQ ID NO: 175 under hybridization conditions comprising at most about 0.9M sodium citrate buffer at a temperature of at least about 37° C.    
     
     
         2 . The isolated Bacillus single-strand binding protein according to  claim 1  wherein the Bacillus species is  Bacillus stearothermophilus.    
     
     
         3 . The isolated Bacillus single-strand binding protein according to  claim 1  wherein the single-strand binding protein comprises the amino acid sequence of SEQ ID NO: 176.  
     
     
         4 . The isolated Bacillus single-strand binding protein according to  claim 1  wherein the single-strand binding protein is encoded by a nucleic acid molecule that hybridizes to the complement of SEQ ID NO: 175 under hybridization conditions comprising at most about 0.9M sodium citrate buffer at a temperature of at least about 37° C.  
     
     
         5 . The isolated Bacillus single-strand binding protein according to  claim 1  wherein the single-strand binding protein is purified.  
     
     
         6 . A DNA-protein complex comprising: 
 a DNA molecule comprising a single-stranded region and a single-strand binding protein according to  claim 1  that is bound to the single-stranded region of the DNA molecule.    
     
     
         7 . A kit comprising: 
 a container that contains therein either a deoxynucleoside triphosphate or a dideoxynucleoside triphosphate;    a container that contains therein a DNA polymerase III-type enzyme complex; and    a container that contains therein a single-strand binding protein according to  claim 1.