Disclosed and claimed are isolated nucleic acid molecules encoding Bacillus stearothermophilus DNA polymerase (DNApolI), including the structural gene for DNApolI, such as DNApolI genes having insertions, deletions, inactivation, or mutations at the 5' end thereof and thus encode Bst polymerase I enzymes which lack or have reduced 3'-5' exonuclease activity, as well as methods for making and using such nucleic acid molecules and such polymerases. For instance, the nucleic acid molecules are useful for making the polymerases, for example, by expression of a vector comprising the nucleic acid molecules; and, the polymerases are useful in DNA sequencing and/or labelling. Thus, disclosed and claimed recombinant DNA clones corresponding to the Bacillus stearothermophilus DNA polymerase (DNApolI) structural gene with deletions at the 5' end. The polymerases from these recombinant DNA clones exhibit DNA synthesis domain activity but have reduced 3' to 5' exonuclease activity. Further, minor modifications at the 5' and 3' ends allow the clones to be manipulated by cloning and expressed as monomeric peptides. These deleted DNA clones give rise to truncated DNApolIK enzymes that are deficient in 3' to 5' exonuclease activity and are useful in nucleic acid synthesis by primer extension reactions, particularly DNA labelling and DNA sequencing reactions. Furthermore, these clones may be combined with other clones in heterologous constructs to create hybrid proteins.

The invention relates to genetical modification of DNA polymerase to reduce its innate selective sequence-related discrimination against incorporation of fluorescent dye-labeled ddCTP and ddATP in the enzymatic reaction for preparation of samples for automated florescent dye-labeled terminator DNA sequencing. The modified DNA polymerases are more resistant to heat inactivation and are more effective in dideoxynucleotide incorporation than current DNA polymerases.

The invention relates to genetic modification of DNA polymerase to reduce innate selective sequence-related discrimination against incorporation of fluorescent dye-labeled ddCTP and ddATP in the enzymatic reaction for preparation of samples for automated fluorescent dye-labeled terminator DNA sequencing. The modified DNA polymerases are more resistant to heat inactivation and are more effective in dideoxynucleotide incorporation than current DNA polymerases.

The invention relates to genetical modification of DNA polymerase to reduce its innate selective sequence-related discrimination against incorporation of fluorescent dye-labeled ddCTP and ddATP in the enzymatic reaction for preparation of samples for automated florescent dye-labeled terminator DNA sequencing. The modified DNA polymerases are more resistant to heat inactivation and are more effective in dideoxynucleotide incorporation than current DNA polymerases.

This invention pertains to a method for generating a pool of nucleic acid fragments useful for in vitro recombination and the creation of novel DNA sequences that encode desirable proteins or enzymes. The invention provides a defined mixture of nucleic acids and methods for use in the synthesis, mutagenesis, and recombination of nucleic acids. Nucleic acids may be synthesized by creating a nucleic acid extension ladder, annealing the extension ladder to template nucleic acids, and further extending the ladder of nucleic acids. The invention also relates to methods for performing repeated cycles of synthesis for the purpose of mutagenesis or recombination, methods for producing mutant peptides and proteins from the mutagenized or recombined nucleic acids, and methods for selecting a peptide, polypeptide or protein having altered biological activities.