The Role of the N-Terminal Domains of Bacterial Initiator DnaA in the Assembly and Regulation of the Bacterial Replication Initiation Complex
| Autor: | Anna Zawilak-Pawlik, Jolanta Zakrzewska-Czerwińska, Małgorzata Nowaczyk |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
DnaA DnaB genetic processes 030106 microbiology Review Biology medicine.disease_cause Pre-replication complex 03 medical and health sciences chemistry.chemical_compound chromosomal replication SeqA protein domain N-terminus of DnaA Genetics medicine orisome DiaA Escherichia coli Gene Genetics (clinical) dnaB helicase oriC Cell biology chemistry SirA health occupations Hda bacteria Dps HobA DNA Function (biology) |
| Zdroj: | Genes |
| ISSN: | 2073-4425 |
| DOI: | 10.3390/genes8050136 |
| Popis: | The primary role of the bacterial protein DnaA is to initiate chromosomal replication. The DnaA protein binds to DNA at the origin of chromosomal replication (oriC) and assembles into a filament that unwinds double-stranded DNA. Through interaction with various other proteins, DnaA also controls the frequency and/or timing of chromosomal replication at the initiation step. Escherichia coli DnaA also recruits DnaB helicase, which is present in unwound single-stranded DNA and in turn recruits other protein machinery for replication. Additionally, DnaA regulates the expression of certain genes in E. coli and a few other species. Acting as a multifunctional factor, DnaA is composed of four domains that have distinct, mutually dependent roles. For example, C-terminal domain IV interacts with double-stranded DnaA boxes. Domain III drives ATP-dependent oligomerization, allowing the protein to form a filament that unwinds DNA and subsequently binds to and stabilizes single-stranded DNA in the initial replication bubble; this domain also interacts with multiple proteins that control oligomerization. Domain II constitutes a flexible linker between C-terminal domains III–IV and N-terminal domain I, which mediates intermolecular interactions between DnaA and binds to other proteins that affect DnaA activity and/or formation of the initiation complex. Of these four domains, the role of the N-terminus (domains I–II) in the assembly of the initiation complex is the least understood and appears to be the most species-dependent region of the protein. Thus, in this review, we focus on the function of the N-terminus of DnaA in orisome formation and the regulation of its activity in the initiation complex in different bacteria. |
| Databáze: | OpenAIRE |
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