RRC ID |
29835
|
Author |
Kogoma T, Subia NL, von Meyenburg K.
|
Title |
Function of ribonuclease H in initiation of DNA replication in Escherichia coli K-12.
|
Journal |
Mol Gen Genet
|
Abstract |
Escherichia coli rnh mutants lacking ribonuclease H (RNase H) activity can tolerate deletion of the origin of DNA Replication (delta oriC) and transposon-insertional inactivation of an initiator gene (dnaA::Tn10). Introduction of the recA200 allele encoding a thermolabile RecA protein into rnh- dnaA::Tn10 and rnh- delta oriC mutants strains rendered DNA synthesis and colony formation of these mutants temperature sensitive. The temperature sensitivity and the broth sensitivity (Srm-) of the rnh- dnaA::Tn10 recA200 strain was suppressed by the presence of plasmids (pBR322 derivatives) carrying dnaA+ only when the intact oriC site was present on the chromosome. Lack of RNase H activity neither promoted replication of minichromosomes (pOC24 and p lambda asn20) in the absence of required DnaA+ protein nor inhibited dnaA+-dependent minichromosome replication. These results led to the conclusion that RNase H is not directly involved in the events leading to initiation of DNA replication at oriC. Rather, it functions as a specificity factor by eliminating certain forms of RNA-DNA hybrids which could otherwise be used to prime DNA replication at sites other than oriC.
|
Volume |
200(1)
|
Pages |
103-9
|
Published |
1985-1-1
|
DOI |
10.1007/BF00383320
|
PMID |
2993805
|
MeSH |
Chromosome Deletion
DNA Replication*
DNA Restriction Enzymes
Endoribonucleases / metabolism*
Escherichia coli / enzymology*
Escherichia coli / genetics
Genotype
Kinetics
Mutation
Plasmids
Ribonuclease H
Species Specificity
Thermodynamics
|
Times Cited |
40
|
WOS Category
|
GENETICS & HEREDITY
BIOCHEMISTRY & MOLECULAR BIOLOGY
|
Resource |
Prokaryotes E. coli |
ME9199
ME9202
ME9204
ME9195
ME9235
ME9196
ME9198 |