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Crystal structure of an OCA-B peptide bound to an Oct-1 POU domain/octamer DNA complex: specific recognition of a protein-DNA interface.

ABSTRACT: We have determined the crystal structure, at 3.2 A, of a ternary complex containing an OCA-B peptide, the Oct-1 POU domain, and an octamer DNA site. The OCA-B peptide binds in the major groove near the center of the octamer site, and its polypeptide backbone forms a pair of hydrogen bonds with the adenine base at position 5 of the octamer DNA. Numerous protein-protein contacts between the OCA-B peptide and the POU domain are also involved in the ternary complex. In particular, the hydrophobic surface from a short alpha-helix of OCA-B helps to stabilize the complex by binding to a hydrophobic pocket on the POU-specific domain. The structure of this ternary complex is consistent with previous biochemical studies and shows how peptide-DNA and peptide-protein contacts from OCA-B provide structural and functional specificity in the regulation of immunoglobulin transcription.

SUBMITTER: Chasman D

PROVIDER: S-EPMC317104 | biostudies-literature | 1999 Oct

REPOSITORIES: biostudies-literature

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Crystal structure of an OCA-B peptide bound to an Oct-1 POU domain/octamer DNA complex: specific recognition of a protein-DNA interface.

Chasman D D Cepek K K Sharp P A PA Pabo C O CO

Genes & development 19991001 20

We have determined the crystal structure, at 3.2 A, of a ternary complex containing an OCA-B peptide, the Oct-1 POU domain, and an octamer DNA site. The OCA-B peptide binds in the major groove near the center of the octamer site, and its polypeptide backbone forms a pair of hydrogen bonds with the adenine base at position 5 of the octamer DNA. Numerous protein-protein contacts between the OCA-B peptide and the POU domain are also involved in the ternary complex. In particular, the hydrophobic su ...[more]

PMID: 10541551

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