Absence of a direct role for RNase HI in initiation of DNA replication at the oriC site on the Escherichia coli chromosome.

AUTOR(ES)

Hong, X

RESUMO

On the basis of the experiments carried out with rnhA224 mutants, we previously concluded that RNase HI is not essential for initiation of Escherichia coli chromosome replication at oriC (T. Kogoma, N.L. Subia, and K. von Meyenburg, Mol. Gen. Genet. 200:103-109, 1985). In light of the recent finding that rnhA224 is a UGA nonsense mutation which can be leaky in certain genetic backgrounds, we reexamined this conclusion with the use of rnhA339 (Null)::cat mutants. The possibility that recB+ is required for initiation at the alternative origins (oriKs) of replication in rnhA mutants was also tested. The results clearly indicated that RNase HI is not essential for oriC initiation and that recB+ is not required for initiation at oriK sites.

Documentos Relacionados

• The DnaA box R4 in the minimal oriC is dispensable for initiation of Escherichia coli chromosome replication.
• The Escherichia coli Fis protein prevents initiation of DNA replication from oriC in vitro.
• The structure of the initiation complex at the replication origin, oriC, of Escherichia coli.
• Importance of state of methylation of oriC GATC sites in initiation of DNA replication in Escherichia coli.
• Mutations in the CCGTTCACA DnaA Box of Mycobacterium tuberculosis oriC That Abolish Replication of oriC Plasmids Are Tolerated on the Chromosome