3O85

Giardia lamblia 15.5kD RNA binding protein

3O85 の概要

• エントリーDOI: 10.2210/pdb3o85/pdb
• 分子名称: Ribosomal protein L7Ae (2 entities in total)
• 機能のキーワード: alpha beta sandwich fold, k-turn rna binding protein, kink turn rna, ribosomal protein
• 由来する生物種: Giardia lamblia
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 25735.98

構造登録者

Biswas, S.,Maxwell, E.S. (登録日: 2010-08-02, 公開日: 2011-03-16, 最終更新日: 2023-09-06)

主引用文献

Biswas, S.,Buhrman, G.,Gagnon, K.,Mattos, C.,Brown, B.A.,Maxwell, E.S.
Comparative analysis of the 15.5kD box C/D snoRNP core protein in the primitive eukaryote Giardia lamblia reveals unique structural and functional features.
Biochemistry, 50:2907-2918, 2011

PubMed Abstract: Box C/D ribonucleoproteins (RNP) guide the 2'-O-methylation of targeted nucleotides in archaeal and eukaryotic rRNAs. The archaeal L7Ae and eukaryotic 15.5kD box C/D RNP core protein homologues initiate RNP assembly by recognizing kink-turn (K-turn) motifs. The crystal structure of the 15.5kD core protein from the primitive eukaryote Giardia lamblia is described here to a resolution of 1.8 Å. The Giardia 15.5kD protein exhibits the typical α-β-α sandwich fold exhibited by both archaeal L7Ae and eukaryotic 15.5kD proteins. Characteristic of eukaryotic homologues, the Giardia 15.5kD protein binds the K-turn motif but not the variant K-loop motif. The highly conserved residues of loop 9, critical for RNA binding, also exhibit conformations similar to those of the human 15.5kD protein when bound to the K-turn motif. However, comparative sequence analysis indicated a distinct evolutionary position between Archaea and Eukarya. Indeed, assessment of the Giardia 15.5kD protein in denaturing experiments demonstrated an intermediate stability in protein structure when compared with that of the eukaryotic mouse 15.5kD and archaeal Methanocaldococcus jannaschii L7Ae proteins. Most notable was the ability of the Giardia 15.5kD protein to assemble in vitro a catalytically active chimeric box C/D RNP utilizing the archaeal M. jannaschii Nop56/58 and fibrillarin core proteins. In contrast, a catalytically competent chimeric RNP could not be assembled using the mouse 15.5kD protein. Collectively, these analyses suggest that the G. lamblia 15.5kD protein occupies a unique position in the evolution of this box C/D RNP core protein retaining structural and functional features characteristic of both archaeal L7Ae and higher eukaryotic 15.5kD homologues.

PubMed: 21366326
DOI: 10.1021/bi1020474

実験手法

X-RAY DIFFRACTION (1.806 Å)