PDBsum entry 1rss

Ribosomal protein

PDB id: 1rss

Contents

Protein chain

140 a.a. *

Waters ×146

* Residue conservation analysis

PDB id:

1rss

Name:

Ribosomal protein

Title:

Ribosomal protein s7 from thermus thermophilus

Structure:

Ribosomal protein s7. Chain: a. Engineered: yes. Mutation: yes

Source:

Thermus thermophilus. Organism_taxid: 274. Cell_line: bl21. Gene: s7. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

1.90Å R-factor: 0.229 R-free: 0.284

Authors:

B.Wimberly,S.White,V.Ramakrishnan

Key ref:

B.T.Wimberly et al. (1997). The structure of ribosomal protein S7 at 1.9 A resolution reveals a beta-hairpin motif that binds double-stranded nucleic acids. Structure, 5, 1187-1198. PubMed id: 9331418 DOI: 10.1016/S0969-2126(97)00269-4

Date:

05-Aug-97 Release date: 11-Feb-98

Protein chain

P17291  (RS7_THET8) -  Small ribosomal subunit protein uS7 from Thermus thermophilus (strain ATCC 27634 / DSM 579 / HB8)

Seq: 156 a.a.

Struc: 140 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1016/S0969-2126(97)00269-4

Structure 5:1187-1198 (1997)

PubMed id: 9331418

The structure of ribosomal protein S7 at 1.9 A resolution reveals a beta-hairpin motif that binds double-stranded nucleic acids.

B.T.Wimberly, S.W.White, V.Ramakrishnan.

ABSTRACT

BACKGROUND: Ribosomal protein S7, a crucial RNA-binding component of the ribosome, is one of two proteins that initiates assembly of the 30S ribosomal subunit. It is required for proper folding of a large 3' domain of 16S ribosomal RNA. S7 regulates its own synthesis by binding to its own mRNA. This ability of S7 to bind both messenger and ribosomal RNAs makes determination of its mode of RNA recognition particularly interesting. RESULTS: The crystal structure of S7 from Thermus thermophilus was determined by a two-wavelength anomalous diffraction experiment using the LIII edge of mercury. The S7 structure consists of a bundle of six helices and an extended beta hairpin between helices 3 and 4, with two or more RNA-binding sites on its surface. The hairpin, along with portions of helices 1, 4 and 6, forms a large, positively charged, concave surface that has the appropriate curvature and dimensions to bind double-stranded RNA. A second putative RNA-binding site comprises parts of loop 2 and the helix 4-loop 5 turn. CONCLUSIONS: Structural similarity between S7 and the IHF/HU family of proteins strongly suggests that the beta hairpin of S7 binds to a groove of double-stranded RNA. The beta hairpin of S7 is also similar to those from other nucleic acid binding proteins, such as ribosomal protein L14 and BIV Tat, suggesting that it belongs to an extended family of such motifs, all of which bind to a groove of double-stranded nucleic acid. The residues in S7 loop 2 that belong to the second putative RNA-binding site may have a role analogous to the N-terminal residues of IHF/HU which grip an unbent portion of double helix.

Selected figure(s)

Figure 4.
Figure 4. RNA-binding regions of S7. (a) Electrostatic surface potential of S7. The potential displayed represents a range from -12 to +12 k[B]T, shown with red as negative and blue as positive. The surface potential calculation and display was done using the program GRASP [84]. (b) Ribbon diagram of a similar view, showing residues that are likely to be involved in RNA-binding. Basic residues are shown in blue and solvent-exposed hydrophobic residues are shown in yellow. The red residues R76 and A116 correspond to the sites of crosslinks to 16S RNA. The figure was produced using the program MOLSCRIPT [82].

The above figure is reprinted by permission from Cell Press: Structure (1997, 5, 1187-1198) copyright 1997.

Figure was selected by an automated process.