Related Experiment Video
Updated: Aug 11, 2026

Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes
Published on: November 1, 2012
The first crystal structure of an archaeal helical repeat protein
Kazunari Yoneda1, Haruhiko Sakuraba, Hideaki Tsuge
1Department of Biological Science and Technology, Faculty of Engineering, University of Tokushima, Tokushima 770-8506, Japan.
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.
Related Concept Videos
Diversity of Archaea III
Protein Organization
Protein Organization
The primary structure of a protein is its amino acid sequence.
Nucleoid
Viruses of Archaea
The DNA Helix

