title: Dimeric structure of the N-terminal domain of PriB protein from Thermoanaerobacter tengcongensis solved ab initio.
abstract: PriB is one of the components of the bacterial primosome, which catalyzes the reactivation of stalled replication forks at sites of DNA damage. The N-terminal domain of the PriB protein from the thermophilic bacterium Thermoanaerobacter tengcongensis (TtePriB) was expressed and its crystal structure was solved at the atomic resolution of 1.09 Å by direct methods. The protein chain, which encompasses the first 104 residues of the full 220-residue protein, adopts the characteristic oligonucleotide/oligosaccharide-binding (OB) structure consisting of a five-stranded β-barrel filled with hydrophobic residues and equipped with four loops extending from the barrel. In the crystal two protomers dimerize, forming a six-stranded antiparallel β-sheet. The structure of the N-terminal OB domain of T. tengcongensis shows significant differences compared with mesophile PriBs. While in all other known structures of PriB a dimer is formed by two identical OB domains in separate chains, TtePriB contains two consecutive OB domains in one chain. However, sequence comparison of both the N-terminal and the C-terminal domains of TtePriB suggests that they have analogous structures and that the natural protein possesses a structure similar to a dimer of two N-terminal domains.
authors.affiliation: Synchrotron Radiation Research Section, MCL, National Cancer Institute, Argonne National Laboratory, Argonne, IL 60439, USA.
authors.forename: Dorothee
authors.initials: D
authors.lastname: Liebschner
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Brzezinski
authors.forename: Miroslawa
authors.initials: M
authors.lastname: Dauter
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Dauter
authors.forename: Marta
authors.initials: M
authors.lastname: Nowak
authors.forename: Józef
authors.initials: J
authors.lastname: Kur
authors.forename: Marcin
authors.initials: M
authors.lastname: Olszewski
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D003001:Cloning, Molecular; D003460:Crystallization; D018360:Crystallography, X-Ray; D019281:Dimerization; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D046968:Thermoanaerobacter / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; C069996:PriB protein (N-terminal)