title: Functional analysis of CedA based on its structure: residues important in binding of DNA and RNA polymerase and in the cell division regulation.
abstract: DnaAcos, a mutant of the initiator DnaA, causes overinitiation of chromosome replication in Escherichia coli, resulting in inhibition of cell division. CedA was found to be a multi-copy suppressor which represses the dnaAcos inhibition of cell division. However, functional mechanism of CedA remains elusive except for previously indicated possibilities in binding to DNA and RNA polymerase. In this study, we searched for the specific sites of CedA in binding of DNA and RNA polymerase and in repression of cell division inhibition. First, DNA sequence to which CedA preferentially binds was determined. Next, the several residues and β4 region in CedA C-terminal domain was suggested to specifically interact with the DNA. Moreover, we found that the flexible N-terminal region was required for tight binding to longer DNA as well as interaction with RNA polymerase. Based on these results, several cedA mutants were examined in ability for repressing dnaAcos cell division inhibition. We found that the N-terminal region was dispensable and that Glu32 in the C-terminal domain was required for the repression. These results suggest that CedA has multiple roles and residues with different functions are positioned in the two regions.
authors.affiliation: Department of Protein Structure, Function and Design and abe@phar.kyushu-u.ac.jp.
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Abe
authors.affiliation: Department of Protein Structure, Function and Design and.
authors.forename: Naoki
authors.initials: N
authors.lastname: Fujisaki
authors.affiliation: Department of Protein Structure, Function and Design and.
authors.forename: Takanori
authors.initials: T
authors.lastname: Miyoshi
authors.affiliation: Department of Protein Structure, Function and Design and.
authors.forename: Noriko
authors.initials: N
authors.lastname: Watanabe
authors.affiliation: Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Katayama
authors.affiliation: Department of Protein Structure, Function and Design and ueda@phar.kyushu-u.ac.jp.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ueda
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology; D001483:Base Sequence; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002455:Cell Division / Q000235:genetics*; D002876:Chromosomes, Bacterial / Q000378:metabolism; D004261:DNA Replication; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D009154:Mutation; D019906:Nuclear Magnetic Resonance, Biomolecular; D017434:Protein Structure, Tertiary
chemical_list: D001426:Bacterial Proteins; C110342:CedA protein, E coli; D018797:Cell Cycle Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria; D029968:Escherichia coli Proteins; D012321:DNA-Directed RNA Polymerases
keywords: CedA; DNA binding; RNA polymerase; cell division