2e0g
From Proteopedia
DnaA N-terminal domain
Structural highlights
FunctionDNAA_ECOLI Plays a key role in the initiation and regulation of chromosomal replication. Binds in an ATP-dependent fashion to the origin of replication (oriC) to initiate formation of the DNA replication initiation complex exactly once per cell cycle. Binds the DnaA box (consensus sequence 5'-TTATC[CA]A[CA]A-3'); subsequent binding of DNA polymerase III subunits leads to replisome formation. The DnaA-ATP form converts to DnaA-ADP; once converted to ADP the protein cannot initiate replication, ensuring only 1 round of replication per cell cycle. DnaA can inhibit its own gene expression as well as that of other genes such as dam, rpoH, ftsA and mioC.[1] [2] [3] Also required for replication of plasmid DNA; binds 4 dnaA boxes in the minimal plasmid RK2 replication origin (oriV).[4] [5] [6] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedDnaA forms a homomultimeric complex with the origin of chromosomal replication (oriC) to unwind duplex DNA. The interaction of the DnaA N terminus with the DnaB helicase is crucial for the loading of DnaB onto the unwound region. Here, we determined the DnaA N terminus structure using NMR. This region (residues 1-108) consists of a rigid region (domain I) and a flexible region (domain II). Domain I has an alpha-alpha-beta-beta-alpha-beta motif, similar to that of the K homology (KH) domain, and has weak affinity for oriC single-stranded DNA, consistent with KH domain function. A hydrophobic surface carrying Trp-6 most likely forms the interface for domain I dimerization. Glu-21 is located on the opposite surface of domain I from the Trp-6 site and is crucial for DnaB helicase loading. These findings suggest a model for DnaA homomultimer formation and DnaB helicase loading on oriC. Structure and function of DnaA N-terminal domains: specific sites and mechanisms in inter-DnaA interaction and in DnaB helicase loading on oriC.,Abe Y, Jo T, Matsuda Y, Matsunaga C, Katayama T, Ueda T J Biol Chem. 2007 Jun 15;282(24):17816-27. Epub 2007 Apr 9. PMID:17420252[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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