Overproduction of DnaA protein stimulates initiation of chromosome and minichromosome replication in Escherichia coli

TY - JOUR

T1 - Overproduction of DnaA protein stimulates initiation of chromosome and minichromosome replication in Escherichia coli

AU - Atlung, T

AU - Løbner-Olesen, A

AU - Hansen, F G

PY - 1987/1

Y1 - 1987/1

N2 - Increased synthesis of DnaA protein, obtained with plasmids carrying the dnaA gene controlled by the heat inducible lambda pL promoter, stimulated initiation of replication from oriC about threefold. The overinitiation was determined both as an increase in copy number of a minichromosome and as an increase in chromosomal gene dosage of oriC proximal DNA. The additional replication forks which were initiated on the chromosome did not lead to an overall increase in DNA content. DNA/DNA hybridization showed an amplification encompassing less than a few hundred kilobases on each side of oriC. Kinetic studies showed that the overinitiation occurred very rapidly after the induction, and that the initiation frequency then decreased to a near normal frequency per oriC. The results indicate that the DnaA protein is one important factor in regulation of initiation of DNA replication from oriC.

AB - Increased synthesis of DnaA protein, obtained with plasmids carrying the dnaA gene controlled by the heat inducible lambda pL promoter, stimulated initiation of replication from oriC about threefold. The overinitiation was determined both as an increase in copy number of a minichromosome and as an increase in chromosomal gene dosage of oriC proximal DNA. The additional replication forks which were initiated on the chromosome did not lead to an overall increase in DNA content. DNA/DNA hybridization showed an amplification encompassing less than a few hundred kilobases on each side of oriC. Kinetic studies showed that the overinitiation occurred very rapidly after the induction, and that the initiation frequency then decreased to a near normal frequency per oriC. The results indicate that the DnaA protein is one important factor in regulation of initiation of DNA replication from oriC.

KW - Bacterial Proteins/genetics

KW - Chromosomes, Bacterial/physiology

KW - DNA Replication

KW - DNA Restriction Enzymes

KW - Escherichia coli/genetics

KW - Gene Amplification

KW - Genes

KW - Genes, Bacterial

KW - Plasmids

M3 - Journal article

C2 - 3033441

SN - 0026-8925

VL - 206

SP - 51

EP - 59

JO - Molecular General Genetics

JF - Molecular General Genetics

IS - 1

ER -