A positively charged residue of phi29 DNA polymerase, highly conserved in DNA polymerases from families A and B, is involved in binding the incoming nucleotide.

ABSTRACT: Alignment of the protein sequence of DNA-dependent DNA polymerases has allowed the definition of a new motif, lying adjacent to motif B in the direction of the N-terminus and therefore named pre-motif B. Both motifs are located in the fingers subdomain, shown to rotate towards the active site to form a dNTP-binding pocket in several DNA polymerases in which a closed ternary complex pol:DNA:dNTP has been solved. The functional significance of pre-motif B has been studied by site-directed mutagenesis of phi29 DNA polymerase. The affinity for nucleotides of phi29 DNA polymerase mutant residues Ile364 and Lys371 was strongly affected in DNA- and terminal protein-primed reactions. Additionally, mutations in Ile364 affected the DNA-binding capacity of phi29 DNA polymerase. The results suggest th

SUBMITTER: Truniger V 

PROVIDER: S-EPMC101840 | biostudies-literature | 2002 Apr

REPOSITORIES: biostudies-literature