Crystallographic snapshots along a protein-induced DNA-bending pathway.
Two new high-resolution cocrystal structures of EcoRV endonuclease bound to DNA show that a large variation in DNA-bending angles is sampled in the ground state binary complex. Together with previous structures, these data reveal a contiguous series of protein conformational states delineating a specific trajectory for the induced-fit pathway. Rotation of the DNA-binding domains, together with movements of two symmetry-related helices binding in the minor groove, causes base unstacking at a key base-pair step and propagates structural changes that assemble the active sites. These structures suggest a complex mechanism for DNA bending that depends on forces generated by interacting protein segments, and on selective neutralization of phosphate charges along the inner face of the bent double helix.
Horton
N C
NC
Department of Chemistry and Biochemistry and Interdepartmental Program in Biochemistry and Molecular Biology, University of California, Santa Barbara, CA 93106-9510, USA.
Perona
J J
JJ
D001665:Binding Sites; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary
D009838:Oligodeoxyribonucleotides; D004247:DNA; D015252:Deoxyribonucleases, Type II Site-Specific; C027440:GATATC-specific type II deoxyribonucleases