2d7h
From Proteopedia
Crystal structure of the ccc complex of the N-terminal domain of PriA
Structural highlights
Function[PRIA_ECOLI] Involved in the restart of stalled replication forks. Recognizes and binds the arrested nascent DNA chain at stalled replication forks. It can open the DNA duplex, via its helicase activity, and promote assembly of the primosome and loading of the major replicative helicase DnaB onto DNA. Is also involved in initiation of normal DNA replication in various plasmids and phages. Binds to branched DNA structures that resemble D-loops or to the primosome assembly site (PAS). Binds to DNA in two distinct modes, either dependent on or independent of the 3' terminus recognition.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] 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 PubMedIn eubacteria, PriA helicase detects the stalled DNA replication forks. This critical role of PriA is ascribed to its ability to bind to the 3' end of a nascent leading DNA strand in the stalled replication forks. The crystal structures in complexes with oligonucleotides and the combination of fluorescence correlation spectroscopy and mutagenesis reveal that the N-terminal domain of PriA possesses a binding pocket for the 3'-terminal nucleotide residue of DNA. The interaction with the deoxyribose 3'-OH is essential for the 3'-terminal recognition. In contrast, the direct interaction with 3'-end nucleobase is unexpected, considering the same affinity for oligonucleotides carrying the four bases at the 3' end. Thus, the N-terminal domain of PriA recognizes the 3'-end base in a base-non-selective manner, in addition to the deoxyribose and 5'-side phosphodiester group, of the 3'-terminal nucleotide to acquire both sufficient affinity and non-selectivity to find all of the stalled replication forks generated during DNA duplication. This unique feature is prerequisite for the proper positioning of the helicase domain of PriA on the unreplicated double-stranded DNA. Structural basis of the 3'-end recognition of a leading strand in stalled replication forks by PriA.,Sasaki K, Ose T, Okamoto N, Maenaka K, Tanaka T, Masai H, Saito M, Shirai T, Kohda D EMBO J. 2007 May 16;26(10):2584-93. doi: 10.1038/sj.emboj.7601697. Epub 2007 Apr , 26. PMID:17464287[11] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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