2K8Q

NMR Structure of Shq1p N-terminal domain

Summary for 2K8Q

• Entry DOI: 10.2210/pdb2k8q/pdb
• NMR Information: BMRB: 15958
• Descriptor: Protein SHQ1 (1 entity in total)
• Functional Keywords: beta-sandwich, cs domain, nucleus, structural protein
• Biological source: Saccharomyces cerevisiae (brewer's yeast,lager beer yeast,yeast)
• Cellular location: Nucleus: P40486
• Total number of polymer chains: 1
• Total formula weight: 15383.34

Authors

Godin, K.S.,Varani, G. (deposition date: 2008-09-18, release date: 2009-05-05, Last modification date: 2024-05-22)

Primary citation

Godin, K.S.,Walbott, H.,Leulliot, N.,van Tilbeurgh, H.,Varani, G.
The box H/ACA snoRNP assembly factor Shq1p is a chaperone protein homologous to Hsp90 cochaperones that binds to the Cbf5p enzyme
J.Mol.Biol., 390:231-244, 2009

PubMed Abstract: Box H/ACA small nucleolar (sno) ribonucleoproteins (RNPs) are responsible for the formation of pseudouridine in a variety of RNAs and are essential for ribosome biogenesis, modification of spliceosomal RNAs, and telomerase stability. A mature snoRNP has been reconstituted in vitro and is composed of a single RNA and four proteins. However, snoRNP biogenesis in vivo requires multiple factors to coordinate a complex and poorly understood assembly and maturation process. Among the factors required for snoRNP biogenesis in yeast is Shq1p, an essential protein necessary for stable expression of box H/ACA snoRNAs. We have found that Shq1p consists of two independent domains that contain casein kinase 1 phosphorylation sites. We also demonstrate that Shq1p binds the pseudourydilating enzyme Cbf5p through the C-terminal domain, in synergy with the N-terminal domain. The NMR solution structure of the N-terminal domain has striking homology to the 'Chord and Sgt1' domain of known Hsp90 cochaperones, yet Shq1p does not interact with the yeast Hsp90 homologue in vitro. Surprisingly, Shq1p has stand-alone chaperone activity in vitro. This activity is harbored by the C-terminal domain, but it is increased by the presence of the N-terminal domain. These results provide the first evidence of a specific biochemical activity for Shq1p and a direct link to the H/ACA snoRNP.

PubMed: 19426738
DOI: 10.1016/j.jmb.2009.04.076

Experimental method

SOLUTION NMR