Sequence determinants of a conformational switch in a protein structure.

ABSTRACT: The Arc repressor of bacteriophage P22 is a dimeric member of the ribbon-helix-helix family of transcription factors. Residues 9-14 of each wild-type Arc subunit pair to form two antiparallel beta-strands and have the alternating pattern of polar and nonpolar residues expected for a beta-ribbon with one solvent-exposed face and one face that forms part of the hydrophobic core. Simultaneously switching Asn-11 to Leu and Leu-12 to Asn changes the local binary sequence pattern to that of an amphipathic helix. Previous studies have shown that this double mutation results in replacement of the wild-type beta-ribbon by two right-handed 3(10)-helices. Moreover, an Arc variant bearing just the Asn-11 --> Leu mutation has an ambiguous binary pattern and can form either the ribbon or the helical str

SUBMITTER: Anderson TA 

PROVIDER: S-EPMC1317976 | biostudies-literature | 2005 Dec

REPOSITORIES: biostudies-literature