Comparative studies of DNA polymerase I of enteric bacteria.

Abstract

DNA polymerases I of several enteric bacteria [Escherichia coli, Shigella sonnei, Salmonella typhimurium, Klebsiella pneumoniae, Serratia marcescens and Pseudomonas aeruginosa] were partially purified and their biochemical, antigenic properties and ability to replicate the DNA of colicin E1 plasmid (Col E1) with the extracts of E. coli pol A were examined. All polymerases had almost the same MW and pH optimum and showed resistance to araCTP [.beta.-D-arabinofuranoside triphosphate] and NEM [N-ethylmaleimide]. They also possessed both 3''-5''- and 5''-3''-exonucleases. The antigenicities and the ability to replicate Col E1 DNA varied with each polymerase. Each polymerase seems to be composed of strongly conserved structure and of the structure which varies from genus to genus. The species-specificities observed in the polymerases seem to reflect the phylogenic relations of bacteria.