title: Structural and Functional Studies of H. seropedicae RecA Protein - Insights into the Polymerization of RecA Protein as Nucleoprotein Filament.
abstract: The bacterial RecA protein plays a role in the complex system of DNA damage repair. Here, we report the functional and structural characterization of the Herbaspirillum seropedicae RecA protein (HsRecA). HsRecA protein is more efficient at displacing SSB protein from ssDNA than Escherichia coli RecA protein. HsRecA also promotes DNA strand exchange more efficiently. The three dimensional structure of HsRecA-ADP/ATP complex has been solved to 1.7 Å resolution. HsRecA protein contains a small N-terminal domain, a central core ATPase domain and a large C-terminal domain, that are similar to homologous bacterial RecA proteins. Comparative structural analysis showed that the N-terminal polymerization motif of archaeal and eukaryotic RecA family proteins are also present in bacterial RecAs. Reconstruction of electrostatic potential from the hexameric structure of HsRecA-ADP/ATP revealed a high positive charge along the inner side, where ssDNA is bound inside the filament. The properties of this surface may explain the greater capacity of HsRecA protein to bind ssDNA, forming a contiguous nucleoprotein filament, displace SSB and promote DNA exchange relative to EcRecA. Our functional and structural analyses provide insight into the molecular mechanisms of polymerization of bacterial RecA as a helical nucleoprotein filament.
authors.affiliation: Department of Physics, Ponta Grossa State University (UEPG), Av. Carlos Cavalcanti, 4748, CEP. 84.030-900, Ponta Grossa, PR, Brazil.
authors.forename: Wellington C
authors.identifier: http://orcid.org/0000-0002-5674-3968
authors.initials: WC
authors.lastname: Leite
authors.affiliation: Department of Structural and Molecular Biology and Genetics, Ponta Grossa State University (UEPG), CEP 84030-900, Ponta Grossa, PR, Brazil.
authors.forename: Carolina W
authors.initials: CW
authors.lastname: Galvão
authors.affiliation: Department of Physics, Ponta Grossa State University (UEPG), Av. Carlos Cavalcanti, 4748, CEP. 84.030-900, Ponta Grossa, PR, Brazil.
authors.forename: Sérgio C
authors.initials: SC
authors.lastname: Saab
authors.affiliation: Department of Chemistry, Ponta Grossa State University (UEPG), CEP 84030-900, Ponta Grossa, PR, Brazil.
authors.forename: Jorge
authors.initials: J
authors.lastname: Iulek
authors.affiliation: Department of Chemistry, Ponta Grossa State University (UEPG), CEP 84030-900, Ponta Grossa, PR, Brazil.
authors.forename: Rafael M
authors.initials: RM
authors.lastname: Etto
authors.affiliation: Department of Biochemistry and Molecular Biology, Federal University of Parana, CEP 81531-980 Curitiba, Brazil.
authors.forename: Maria B R
authors.initials: MB
authors.lastname: Steffens
authors.affiliation: Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706-1544, United States of America.
authors.forename: Sindhu
authors.initials: S
authors.lastname: Chitteni-Pattu
authors.affiliation: Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706-1544, United States of America.
authors.forename: Tyler
authors.initials: T
authors.lastname: Stanage
authors.affiliation: Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, 53706, United States of America.
authors.forename: James L
authors.initials: JL
authors.lastname: Keck
authors.affiliation: Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706-1544, United States of America.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Cox
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020134:Catalytic Domain; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation; D042803:Herbaspirillum / Q000201:enzymology*; D008958:Models, Molecular; D009698:Nucleoproteins / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D055503:Protein Multimerization; D011938:Rec A Recombinases / Q000737:chemistry* / Q000378:metabolism*; D011994:Recombinant Proteins; D055672:Static Electricity; D013329:Structure-Activity Relationship
chemical_list: D001426:Bacterial Proteins; D009698:Nucleoproteins; D011994:Recombinant Proteins; D004247:DNA; D011938:Rec A Recombinases