The present disclosure provides a fusion polypeptide comprising: a) an enzymatically active RNA-guided endonuclease that introduces a single-stranded break in a target DNA; and b) an error-prone DNA polymerase. The present disclosure provides a system comprising: a) a fusion polypeptide of the present disclosure; and b) a guide RNA. The present disclosure provides a cell comprising a fusion polypeptide of the present disclosure, or a system of the present disclosure. The present disclosure provides a method of mutagenizing a target polynucleotide.

The disclosure provides a high-fidelity polymerase with preference for gapped DNA and use thereof. The Klenow fragment (KlenDr) derived from Deinococcus radiodurans DNA polymerase I, which has the high-fidelity polymerization characteristics, is independent of 3′-5′ proofreading exonuclease activity, has the preference for binding gapped DNA, and is different from the existing commercial high-fidelity polymerase. Due to the specific affinity of KlenDr to gapped DNA substrate, the 3′ end of the forward primer will not be cut off, and the downstream nucleotide chain is rarely replaced.

Provided are a Phi29 DNA polymerase mutant with improved thermal stability and an use thereof in sequencing. The phi29 DNA polymerase mutant is represented by A) or B) below: the DNA polymerase mutant represented by the A) is a protein having DNA polymerase activity that is obtained by modifying at least one amino acid residue(s) in the following six sites in a phi29 DNA polymerase amino acid sequence: the 97-th, 123-th, 217-th, 224-th, 515-th, and 474-th sites; the DNA polymerase mutant represented by the B) is a protein having DNA polymerase activity that is derived from the A) by adding a tag sequence to a terminal of the amino acid sequence of the protein represented by the A).

The invention relates to modified polymerase enzymes which exhibit improved incorporation of nucleotide analogues bearing substituents at the 3′ position of the sugar moiety that are larger in size than the naturally occurring 3′hydroxyl group. Also described are methods of using the polymerases to incorporate nucleotides into polynucleotides, particularly in the context of DNA sequencing.

This invention relates to mutant Taq DNA polymerase having an enhanced template discrimination activity compared with an unmodified Taq DNA polymerase of SEQ ID NO.:1, wherein the amino acid sequence of the mutant Taq DNA polymerase consists of substitutions at residue positions 783, 784, or a combination of 783 and 784 of the unmodified Taq DNA polymerase of SEQ ID NO.:1.

Disclosed herein, inter alia, are compounds, modified nucleotides, compositions, and methods of using the same.

A composition comprising a thermostable DNA polymerase; and a PCR inhibitor blocking agent, wherein the PCR inhibitor blocking agent is present in an amount effective to enhance tolerance of an assembled PCR to a PCR inhibitor.

Provided are mutant polymerases having DNA polymerase activity and reverse transcriptase activity or strand displacement activity, along with target nucleic acid amplification methods employing such mutant polymerases.

Presented herein are altered polymerase enzymes for improved incorporation of nucleotides and nucleotide analogues, in particular altered polymerases that maintain high fidelity under reduced incorporation times, as well as methods and kits using the same.

This disclosure provides an E. coli strain, which lacks thioredoxin reductase activity encoded by trxB and thioredoxin 1 activity encoded by trxA, and glutathione reductase activity encoded by gor. Said E. coli strain expresses a mutated AhpC protein having glutathione reductase activity and a cytosolic prokaryotic disulfide isomerase. The E. coli strain has an oxidative cytosol and can be used to efficiently produce proteins having disulfide bonds.