title: S6 permutein shows that the unusual target topology is not responsible for the absence of rigid tertiary structure in de novo protein albebetin.
abstract: Ribosomal protein S6 from Thermus thermophilus was modified to form the unusual unique topology designed earlier for a de novo protein albebetin. The S6 gene was cloned, sequenced and circularly permutated by means of genetic engineering methods. The permutated gene was expressed in Escherichia coli and the permutein was isolated and investigated by means of circular dichroism, fluorescence spectroscopy and scanning microcalorimetry. The permutated protein revealed a pronounced secondary structure close to that of the wild type S6 protein and a rigid tertiary structure possessing cooperative temperature melting. It means that the unusual new topology of albebetin is compatible with a rigid tertiary structure, it may be realized in natural proteins and it is not responsible for the absence of rigid structure in albebetin.
authors.affiliation: Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow. zied@nmr.ru
authors.forename: Z K
authors.initials: ZK
authors.lastname: Abdullaev
authors.forename: R F
authors.initials: RF
authors.lastname: Latypov
authors.forename: A Y
authors.initials: AY
authors.lastname: Badretdinov
authors.forename: D A
authors.initials: DA
authors.lastname: Dolgikh
authors.forename: A V
authors.initials: AV
authors.lastname: Finkelstein
authors.forename: V N
authors.initials: VN
authors.lastname: Uversky
authors.forename: M P
authors.initials: MP
authors.lastname: Kirpichnikov
mesh_terms: D002942:Circular Dichroism; D003001:Cloning, Molecular; D004926:Escherichia coli; D011489:Protein Denaturation; D015202:Protein Engineering; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D038601:Ribosomal Protein S6; D012269:Ribosomal Proteins / Q000096:biosynthesis / Q000737:chemistry*; D013816:Thermodynamics; D014508:Urea
chemical_list: D011506:Proteins; D011994:Recombinant Proteins; D038601:Ribosomal Protein S6; D012269:Ribosomal Proteins; C074146:albebetin; D014508:Urea