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Hda, a novel DnaA‐related protein, regulates the replication cycle in Escherichia coli
Author(s) -
Kato Junichi,
Katayama Tsutomu
Publication year - 2001
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/20.15.4253
Subject(s) - dnaa , biology , dna replication , dnab helicase , seqa protein domain , pre replication complex , origin recognition complex , replication factor c , prokaryotic dna replication , polymerase , dna clamp , microbiology and biotechnology , dna polymerase ii , ter protein , control of chromosome duplication , eukaryotic dna replication , dna , biochemistry , gene , helicase , rna , reverse transcriptase
The bacterial DnaA protein binds to the chromosomal origin of replication to trigger a series of initiation reactions, which leads to the loading of DNA polymerase III. In Escherichia coli , once this polymerase initiates DNA synthesis, ATP bound to DnaA is efficiently hydrolyzed to yield the ADP‐bound inactivated form. This negative regulation of DnaA, which occurs through interaction with the β‐subunit sliding clamp configuration of the polymerase, functions in the temporal blocking of re‐initiation. Here we show that the novel DnaA‐related protein, Hda, from E.coli is essential for this regulatory inactivation of DnaA in vitro and in vivo . Our results indicate that the hda gene is required to prevent over‐initiation of chromosomal replication and for cell viability. Hda belongs to the chaperone‐like ATPase family, AAA + , as do DnaA and certain eukaryotic proteins essential for the initiation of DNA replication. We propose that the once‐per‐cell‐cycle rule of replication depends on the timely interaction of AAA + proteins that comprise the apparatus regulating the activity of the initiator of replication.