PDBsum entry 3eud

Nuclear protein

PDB id: 3eud

Contents

Protein chains

99 a.a. *

92 a.a. *

Waters ×103

* Residue conservation analysis

PDB id:

3eud

Name:

Nuclear protein

Title:

Structure of the cs domain of the essential h/aca rnp assembly protein shq1p

Structure:

Protein shq1. Chain: a, b, c, d, e, f. Fragment: cs domain, unp residues 1-98. Synonym: small nucleolar rnas of the box h/aca family quantitative accumulation protein 1. Engineered: yes

Source:

Saccharomyces cerevisiae. Baker's yeast, yeast. Organism_taxid: 4932. Gene: shq1, yil104c. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.40Å R-factor: 0.228 R-free: 0.248

Authors:

M.Singh,D.Cascio,F.A.Gonzales,N.Heckmann,G.Chanfreau,J.Feigon

Key ref:

M.Singh et al. (2009). Structure and Functional Studies of the CS Domain of the Essential H/ACA Ribonucleoparticle Assembly Protein SHQ1. J Biol Chem, 284, 1906-1916. PubMed id: 19019820 DOI: 10.1074/jbc.M807337200

Date:

09-Oct-08 Release date: 18-Nov-08

Protein chains

P40486  (SHQ1_YEAST) -  Protein SHQ1 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 507 a.a.

Struc: 99 a.a.

Protein chains

P40486  (SHQ1_YEAST) -  Protein SHQ1 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 507 a.a.

Struc: 92 a.a.

DOI no: 10.1074/jbc.M807337200

J Biol Chem 284:1906-1916 (2009)

PubMed id: 19019820

Structure and Functional Studies of the CS Domain of the Essential H/ACA Ribonucleoparticle Assembly Protein SHQ1.

M.Singh, F.A.Gonzales, D.Cascio, N.Heckmann, G.Chanfreau, J.Feigon.

ABSTRACT

H/ACA ribonucleoprotein particles are essential for ribosomal RNA and telomerase RNA processing and metabolism. Shq1p has been identified as an essential eukaryotic H/ACA small nucleolar (sno) ribonucleoparticle (snoRNP) biogenesis and assembly factor. Shq1p is postulated to be involved in the early biogenesis steps of H/ACA snoRNP complexes, and Shq1p depletion leads to a specific decrease in H/ACA small nucleolar RNA levels and to defects in ribosomal RNA processing. Shq1p contains two predicted domains as follows: an N-terminal CS (named after CHORD-containing proteins and SGT1) or HSP20-like domain, and a C-terminal region of high sequence homology called the Shq1 domain. Here we report the crystal structure and functional studies of the Saccharomyces cerevisiae Shq1p CS domain. The structure consists of a compact anti-parallel beta-sandwich fold that is composed of two beta-sheets containing four and three beta-strands, respectively, and a short alpha-helix. Deletion studies showed that the CS domain is required for the essential functions of Shq1p. Point mutations in residues Phe-6, Gln-10, and Lys-80 destabilize Shq1p in vivo and induce a temperature-sensitive phenotype with depletion of H/ACA small nucleolar RNAs and defects in rRNA processing. Although CS domains are frequently found in co-chaperones of the Hsp90 molecular chaperone, no interaction was detected between the Shq1p CS domain and yeast Hsp90 in vitro. These results show that the CS domain is essential for Shq1p function in H/ACA snoRNP biogenesis in vivo, possibly in an Hsp90-independent manner.

Selected figure(s)

Figure 2.
^1H-^15N HSQC spectra of the Shq1p CS domain. Overlay of ^1H-^15N HSQC spectra of Shq1p CS (red) and CS-L (cyan) proteins. Assignments of amide resonances of CS are indicated (K0 is a residue from the tag).

Figure 8.
Comparison of Shq1p CS domain, Sgt1 CS domain, Sba1, and p23. A, sequence alignment of Shq1p CS domain, Sgt1 CS domain, Sba1, and p23. The boundaries of the constructs used for NMR or crystallization studies are shown in parentheses. For Shq1p, additional C-terminal residues beyond the end of Shq1p CS are shown in gray for comparison with the other domains. The residues of the Sba1 and p23 that are involved in binding with Hsp90 are shown in blue and cyan box, respectively. B, ribbon representations of the structures of Shq1p CS domain, Sgt1 CS domain (Protein Data Bank code 1RL1), p23 (Protein Data Bank code 1EJF), and Sba1 (Protein Data Bank code 2CG9). The C-terminal α-helix found in Shq1p CS and the β-strand in the equivalent region of p23 and Sba1 are shown in cyan. C, surface representations of the CS domains showing the charge distributions. The Shq1p CS domain does not have the extensive basic surface in comparison with the Sgt1 CS domain, p23, and Sba1.

The above figures are reprinted from an Open Access publication published by the ASBMB: J Biol Chem (2009, 284, 1906-1916) copyright 2009.

Figures were selected by an automated process.