tailieunhanh - Báo cáo khoa học: Common mode of DNA binding to cold shock domains Crystal structure of hexathymidine bound to the domain-swapped form of a major cold shock protein from Bacillus caldolyticus

Bacterial cold shock proteins (CSPs) regulate cellular adaptation to cold stress. Functions ascribed to CSP include roles as RNA chaperones and in transcription antitermination. We present the crystal structure of the Bacil-lus caldolyticus CSP (Bc-Csp) in complex with hexathymidine (dT6)ata resolution of A ˚ . | ỊFEBS Journal Common mode of DNA binding to cold shock domains Crystal structure of hexathymidine bound to the domain-swapped form of a major cold shock protein from Bacillus caldolyticus Klaas E. A. Max1 Markus Zeeb2 Ralf Bienert1 Jochen Balbach2 t and Udo Heinemann1 3 1 Max-Delbruck-Centrum fur Molekulare Medizin Berlin-Buch Germany 2 Lehrstuhl fur Biochemie Universitat Bayreuth Germany 3 Institut fur Chemie und Biochemie Freie Universitat Berlin Germany Keywords cold shock response domain swap OB-fold protein-DNA complex single-stranded DNA Correspondence U. Heinemann Max-Delbruck-Centrum fijr Molekulare Medizin Robert-Rossle-Str. 10 13125 Berlin Germany Fax 49 30 9406 2548 Tel 49 30 9406 3420 E-mail heinemann@ Present address Department of Molecular Biology The Scripps Research Institute La Jolla CA USA fFachgruppe Biophysik Fachbereich Physik Martin-Luther-Universitat Halle-Wittenberg Germany Received 30 October 2006 revised 22 December 2006 accepted 22 December 2006 doi Bacterial cold shock proteins CSPs regulate cellular adaptation to cold stress. Functions ascribed to CSP include roles as RNA chaperones and in transcription antitermination. We present the crystal structure of the Bacillus caldolyticus CSP Bc-Csp in complex with hexathymidine dT6 at a resolution of A. Bound to dT6 crystalline Bc-Csp forms a domainswapped dimer in which b strands 1-3 associate with strands 4 and 5 from the other subunit to form a closed b barrel and vice versa. The globular units of dimeric Bc-Csp closely resemble the well-known structure of monomeric CSP. Structural reorganization from the monomer to the domain-swapped dimer involves a strictly localized change in the peptide bond linking Glu36 and Gly37 of Bc-Csp. Similar structural reorganizations have not been found in any other CSP or oligonucleotide oligosac-charide-binding fold structures. Each dT6 ligand is bound to one globular unit of Bc-Csp via an amphipathic .