Recombinant DNA polymerase for improved incorporation of nucleotide analogues
A composition comprising a recombinant DNA polymerase and 3′-esterified nucleotide analogues is provided. The recombinant DNA polymerase includes an amino acid sequence that is at least 90% homology with 9° N DNA polymerase (SEQ ID NO: 1), and the recombinant DNA polymerase includes at least two mutations at the positions corresponding to amino acid residues 141 and 143 of the 9° N DNA polymerase. A recombinant DNA polymerase is further provided. The recombinant DNA polymerase includes an amino acid sequence that is at least 90% homology with 9° N-III DNA polymerase (SEQ ID NO: 3), and the recombinant DNA polymerase includes one or two mutations at the positions corresponding to amino acid residue 480 and 486 of the 9° N-III DNA polymerase. A method of performing a polymerization reaction is also provided.
1. A recombinant DNA polymerase having at least 99% sequence homology with the 9° N-III DNA polymerase of SEQ ID NO: 3 and the recombinant DNA polymerase comprises one or two mutations at the position corresponding to the amino acid residue 480 and 486 of the 9° N-III DNA polymerase of SEQ ID NO: 3.
2. The recombinant DNA polymerase of claim 1 , wherein the mutation at the amino acid residue 480 is D480A, D480C, D480F, D480G, D480H, D480I, D480M, D480N, D480P, D480Q, D480R or D480S.
3. The recombinant DNA polymerase of claim 1 , wherein the mutation at the amino acid residue 486 is I486A, I486F, I486G, I486H, I486L, I486M, I486P, I486R, I486V, I486W or 1486Y.
4. The recombinant DNA polymerase of claim 1 , wherein the recombinant DNA polymerase incorporates 3′-esterified nucleotide analogue in a template-dependent manner into a nascent strand, and the 3′-esterified nucleotide analogue is 3′-esterified nucleotide, 3′-ester-dye analogue or 3′-ester-dye analogue with quencher linked to phosphate group (3′-ester-dye/5′-Q).
5. The recombinant DNA polymerase of claim 4 , wherein the 3′-ester-dye/5′-Q has the following formula (I):
wherein m is an integer and 1≤m≤10, L represents the linker group;
Rm and Rm+1 vary as m varies, and when m is larger than 1, Rm refers to a set of functional groups ranging from R1 to Rm, each of Rm may represent independently hydrogen (H) or a functional group consisting of a linker group Lm and a Fm, while Rm+1 may represent hydrogen (H) or a functional group consisting of a linker group Lm+1 and the Fm+1; the F, Fm or Fm+1 is independently a fluorescent dye or a quencher; the linker group Lm or Lm+1 is independently selected from alkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocyclyl, polyethylene glycol, ester, amino, sulfonyl, or a combination thereof;
B represents a base selected from adenine, cytosine, guanine, thymine, uracil, hypoxanthine or 5-methylcytosine;
Z is independently selected from hydrogen, hydroxyl, thiol, halogen, or amino group; and
Y in Formula I represents oxygen (O) or sulfur (S).