Article

Crystal structure of a fibrillarin homologue from Methanococcus jannaschii, a hyperthermophile, at 1.6 A resolution. EMBO J

Department of Chemistry, University of California, Berkeley, CA 94720, USA.
The EMBO Journal (Impact Factor: 10.75). 03/2000; 19(3):317-23. DOI: 10.1093/emboj/19.3.317
Source: PubMed

ABSTRACT Fibrillarin is a phylogenetically conserved protein essential for efficient processing of pre-rRNA through its association with a class of small nucleolar RNAs during ribosomal biogenesis. The protein is the antigen for the autoimmune disease scleroderma. Here we report the crystal structure of the fibrillarin homologue from Methanococcus jannaschii, a hyperthermophile, at 1.6 A resolution. The structure consists of two domains, with a novel fold in the N-terminal region and a methyltransferase-like domain in the C-terminal region. Mapping temperature-sensitive mutations found in yeast fibrillarin Nop1 to the Methanococcus homologue structure reveals that many of the mutations cluster in the core of the methyltransferase-like domain.

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    • "Boxes C/D (or C9/D9), which form a specific structural motif termed kink-turn (K-turn), are required for the assembly of four core proteins, namely, 15.5K, Nop56, Nop58, and a methyltransferase, designated as Fibrillarin, to build up a functional ribonucleo-protein particle (C/D snoRNP) (Samarsky et al. 1998; Watkins et al. 2000; Klein et al. 2001; Watkins et al. 2002; Tran et al. 2004). Fibrillarin is necessary and required to localize the mature snoRNP complex to the nucleolus and also catalyzes the formation of the 29-O-Methylribose within target RNAs (Lafontaine and Tollervey 2000; Wang et al. 2000a; Verheggen et al. 2001). As shown for canonical snoRNPs, the nucleolar localization of the MBII-52 snoRNA, although lacking complementarity to rRNA or snRNA targets, has been demonstrated by FISH analysis (Vitali et al. 2005). "
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