title: The first crystal structure of an archaeal helical repeat protein.
abstract: The crystal structure of ST1625p, a protein encoded by a hypothetical open reading frame ST1625 in the genome of the hyperthermophilic archaeon Sulfolobus tokodaii, was determined at 2.2 A resolution. The only sequence similarity exhibited by the amino-acid sequence of ST1625p was a 33% identity with the sequence of SSO0983p from S. solfataricus. The 19 kDa monomeric protein was observed to consist of a right-handed superhelix assembled from a tandem repeat of ten alpha-helices. A structural homology search using the DALI and MATRAS algorithms indicates that this protein can be classified as a helical repeat protein.
authors.affiliation: Department of Biological Science and Technology, Faculty of Engineering, University of Tokushima, Tokushima 770-8506, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Yoneda
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Sakuraba
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tsuge
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Katunuma
authors.forename: Seiki
authors.initials: S
authors.lastname: Kuramitsu
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kawabata
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Ohshima
mesh_terms: D000465:Algorithms; D000595:Amino Acid Sequence; D001105:Archaea / Q000378:metabolism*; D019843:Archaeal Proteins / Q000737:chemistry*; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray / Q000379:methods*; D004926:Escherichia coli / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D016944:Sulfolobus / Q000201:enzymology*
chemical_list: D019843:Archaeal Proteins