Mechanism of dnaB protein action. IV. General priming of DNA replication by dnaB protein and primase compared with RNA polymerase

J Biol Chem. 1981 May 25;256(10):5267-72.


The general priming system of dnaB protein and primase (Arai, K., and Kornberg, A. (1979) Proc. Natl. Acad. Sci. U. S. A. 76, 4308-4312) when compared with priming by RNA polymerase shows a number of striking differences. The general priming system is initiated primarily at single-stranded region(S), being active only on single-stranded DNAs (phages and homopolymers) and inhibited by single-stranded DNA binding protein (SSB). Transcripts are only 10 to 60 residues long. By contrast, RNA priming by RNA polymerase is initiated at base-paired regions that are not destabilized by SSB (Geider, K., Beck, E., and Schaller, H. (1978) Proc. Natl. Acad. Sci. U. S. A. 76, 645-649) and transcripts on DNA not coated with SSB are generally longer. In general priming, ATP (or GTP) has three functions: (i) an allosteric effect on dnaB protein in which the nonhydrolyzed analogs adenosine-5'-O-(3'-thiotriphosphate) (or guanosine-5'-O-(3'-thiotriphosphate) can substitute, (ii) initiation of primer synthesis which can incorporate deoxy-, as well as ribonucleotides, and (iii) elongation of the primer, in which the beta, gamma-imido analog can replace ATP (or GTP). An allosteric effect of ATP on RNA polymerase has not been demonstrated, nor has the facile synthesis of hybrid transcripts of ribo- and deoxyribonucleotides.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Proteins / metabolism*
  • Base Composition
  • DNA / metabolism
  • DNA Polymerase III / metabolism*
  • DNA Primase
  • DNA Replication*
  • DNA, Viral
  • DNA-Directed DNA Polymerase / metabolism*
  • DNA-Directed RNA Polymerases / metabolism*
  • Kinetics
  • Phosphoric Monoester Hydrolases / metabolism*
  • Polynucleotides
  • RNA Nucleotidyltransferases / metabolism*
  • Templates, Genetic


  • Bacterial Proteins
  • DNA, Viral
  • Polynucleotides
  • DNA
  • DNA Primase
  • RNA Nucleotidyltransferases
  • DNA-Directed RNA Polymerases
  • DNA Polymerase III
  • DNA-Directed DNA Polymerase
  • Phosphoric Monoester Hydrolases