Binding of the DNA primase of bacteriophage T7 to its recognition sequence in DNA is modulated by the zinc-binding domain Academic Article uri icon

abstract

  • The zinc-binding domains (ZBD) of prokaryotic DNA primases are critical for recognition of specific sequence in ssDNA at which primers are synthesized. ZBDs are structurally conserved in primases but they direct recognition of distinct trinucleotide sequences. In order to determine regions of the ZBD responsible for sequence-specific recognition, we carried out homolog-scanning mutagenesis on T7 DNA primase using a bacterial homolog from Bacillus stearothermophilus. Substitution of a five amino acid residue segment in the ZBD eliminates the ability of the primase to synthesize primers from a specific template sequence. The role of residues neighboring two cysteins (Cys17 and Cys20) in the primase was investigated by generating a library comprised of multiple amino acid substitutions at positions of Pro16, Asp18, and Asn19 followed by genetic screening for functional gene 4 …

publication date

  • January 1, 2010