Molecular Weight of Deoxyribonucleic Acid Synthesized During Initiation of Chromosome Replication in Escherichia coli
AUTOR(ES)
Kuempel, Peter L.
RESUMO
Alkaline sucrose gradients were used to study the molecular weight of deoxyribonucleic acid (DNA) synthesized during the initiation of chromosome replication in Escherichia coli 15 TAU-bar. The experiments were conducted to determine whether newly synthesized, replication origin DNA is attached to higher-molecular-weight parental DNA. Little of the DNA synthesized after readdition of required amino acids to cells previously deprived of the amino acids was present in DNA with a molecular weight comparable to that of the parental DNA. The newly synthesized, low-molecular-weight DNA rapidly appeared in higher-molecular-weight material, but there was an upper limit to the size of this intermediate-molecular-weight DNA. This limit was not observed when exponentially growing cells converted newly synthesized DNA to higher-molecular-weight material. The size of the intermediate-molecular-weight DNA was related to the age of the replication forks, and the size increased as the replication forks moved further from the replication origin. The results indicate that the newly synthesized replication origin DNA is not attached to parental DNA, but it is rapidly attached to the growing strands that extend from the replication fork to the replication origin, or to the other replication fork if replication is bidirectional. Experiments are reported which demonstrate that the DNA investigated was from the vicinity of the replication origin and was not plasmid DNA or DNA from random positions on the chromosome.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=251386Documentos Relacionados
- Replication of Deoxyribonucleic Acid in Escherichia coli C Mutants Temperature Sensitive in the Initiation of Chromosome Replication
- Initiation of deoxyribonucleic acid replication in Escherichia coli B: uncoupling from mass/deoxyribonucleic acid ratio.
- Accumulation of the capacity of initiation of deoxyribonucleic acid replication in Escherichia coli.
- Deoxyribonucleic acid-membrane interactions near the origin of replication and initiation of deoxyribonucleic acid synthesis in Escherichia coli.
- Chromosome structure of Escherichia coli mutants temperature sensitive for deoxyribonucleic acid replication.