PortEco logo

PMID:20132442

From EcoliWiki
Jump to: navigation, search

Contents

Citation

Nakamura, K and Katayama, T (2010) Novel essential residues of Hda for interaction with DnaA in the regulatory inactivation of DnaA: unique roles for Hda AAA Box VI and VII motifs. Mol. Microbiol. 76:302-17

Abstract

Escherichia coli ATP-DnaA initiates chromosomal replication. For preventing extra-initiations, a complex of ADP-Hda and the DNA-loaded replicase clamp promotes DnaA-ATP hydrolysis, yielding inactive ADP-DnaA. However, the Hda-DnaA interaction mode remains unclear except that the Hda Box VII Arg finger (Arg-153) and DnaA sensor II Arg-334 within each AAA(+) domain are crucial for the DnaA-ATP hydrolysis. Here, we demonstrate that direct and functional interaction of ADP-Hda with DnaA requires the Hda residues Ser-152, Phe-118 and Asn-122 as well as Hda Arg-153 and DnaA Arg-334. Structural analyses suggest intermolecular interactions between Hda Ser-152 and DnaA Arg-334 and between Hda Phe-118 and the DnaA Walker B motif region, in addition to an intramolecular interaction between Hda Asn-122 and Arg-153. These interactions likely sustain a specific association of ADP-Hda and DnaA, promoting DnaA-ATP hydrolysis. Consistently, ATP-DnaA and ADP-DnaA interact with the ADP-Hda-DNA-clamp complex with similar affinities. Hda Phe-118 and Asn-122 are contained in the Box VI region, and their hydrophobic and electrostatic features are basically conserved in the corresponding residues of other AAA(+) proteins, suggesting a conserved role for Box VI. These findings indicate novel interaction mechanisms for Hda-DnaA as well as a potentially fundamental mechanism in AAA(+) protein interactions.

Links

PubMed Online version:10.1111/j.1365-2958.2010.07074.x

Keywords

Adenosine Triphosphatases/genetics; Adenosine Triphosphatases/metabolism; Amino Acid Sequence; Bacterial Proteins/antagonists & inhibitors; Bacterial Proteins/metabolism; DNA-Binding Proteins/antagonists & inhibitors; DNA-Binding Proteins/metabolism; Escherichia coli/physiology; Escherichia coli Proteins/genetics; Escherichia coli Proteins/metabolism; Gene Expression Regulation, Bacterial; Models, Molecular; Molecular Sequence Data; Protein Binding; Protein Interaction Mapping; Protein Structure, Tertiary

Significance

You can help EcoliWiki by summarizing why this paper is useful

Useful Materials and Methods

You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.

Annotations

Gene product Qualifier GO ID GO term name Evidence Code with/from Aspect Notes Status

EcoliWiki Links

Add links to pages that link here (e.g. gene, product, method pages)

See also

References

See Help:References for how to manage references in EcoliWiki.