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X-ray structure analysis of a designed oligomeric miniprotein reveals a discrete quaternary architecture.

ABSTRACT: The x-ray crystal structure of an oligomeric miniprotein has been determined to a 1.2-A resolution by means of multiwavelength anomalous diffraction phasing with selenomethionine analogs that retain the biophysical characteristics of the native peptide. Peptide 1, comprising alpha and beta secondary structure elements with only 21 aa per monomer, associates as a discrete tetramer. The peptide adopts a previously uncharacterized quaternary structure in which alpha and beta components interact to form a tightly packed and well defined hydrophobic core. The structure provides insight into the origins of the unusual thermal stability of the oligomer. The miniprotein shares many characteristics of larger proteins, including cooperative folding, lack of 1-anilino-8-naphthalene sulfonate binding, and limited deuterium exchange, and possesses a buried surface area typical of native proteins.

SUBMITTER: Ali MH

PROVIDER: S-EPMC514454 | biostudies-literature | 2004 Aug

REPOSITORIES: biostudies-literature

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X-ray structure analysis of a designed oligomeric miniprotein reveals a discrete quaternary architecture.

Ali Mayssam H MH Peisach Ezra E Allen Karen N KN Imperiali Barbara B

Proceedings of the National Academy of Sciences of the United States of America 20040809 33

The x-ray crystal structure of an oligomeric miniprotein has been determined to a 1.2-A resolution by means of multiwavelength anomalous diffraction phasing with selenomethionine analogs that retain the biophysical characteristics of the native peptide. Peptide 1, comprising alpha and beta secondary structure elements with only 21 aa per monomer, associates as a discrete tetramer. The peptide adopts a previously uncharacterized quaternary structure in which alpha and beta components interact to ...[more]

PMID: 15302930

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