Structure and stability of the N-terminal domain of the ribosomal protein L9: evidence for rapid two-state folding.


Abstract

The N-terminal domain, residues 1-56, of the ribosomal protein L9 has been chemically synthesized. The isolated domain is monomeric as judged by analytical ultracentrifugation and concentration-dependent CD. Complete 1H chemical shift assignments were obtained using standard methods. 2D-NMR experiments show that the isolated domain adopts the same structure as seen in the full-length protein. It consists of a three-stranded antiparallel beta-sheet sandwiched between two helixes. Thermal and urea unfolding transitions are cooperative, and the unfolding curves generated from different experimental techniques, 1D-NMR, far-UV CD, near-UV CD, and fluorescence, are superimposable. These results suggest that the protein folds by a two-state mechanism. The thermal midpoint of folding is 77 +/- 2 degrees C at pD 8.0, and the domain has a delta G degree folding = 2.8 +/- 0.8 kcal/mol at 40 degrees C, pH 7.0. Near the thermal midpoint of the unfolding transition, the 1D-NMR peaks are significantly broadened, indicating that folding is occurring on the intermediate exchange time scale. The rate of folding was determined by fitting the NMR spectra to a two-state chemical exchange model. Similar folding rates were measured for Phe 5, located in the first beta-strand, and for Tyr 25, located in the short helix between strands two and three. The domain folds extremely rapidly with a folding rate constant of 2000 s-1 near the midpoint of the equilibrium thermal unfolding transition. Study holds ProTherm entries: 8825, 8826, 8827 Extra Details: antiparallel beta-sheet; cooperative; two-state mechanism;,equilibrium thermal unfolding transition

Submission Details

ID: MeJmhRyk

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:37 p.m.

Version: 1

Publication Details
Kuhlman B;Boice JA;Fairman R;Raleigh DP,Biochemistry (1998) Structure and stability of the N-terminal domain of the ribosomal protein L9: evidence for rapid two-state folding. PMID:9454593
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P
 

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)


Relevant PDB Entries

Structure ID Release Date Resolution Structure Title
1CQU 2002-04-27 SOLUTION STRUCTURE OF THE N-TERMINAL DOMAIN OF RIBOSOMAL PROTEIN L9
2HBA 2007-05-29 1.25 Crystal Structure of N-terminal Domain of Ribosomal Protein L9 (NTL9) K12M
2HVF 2007-06-12 1.57 Crystal Structure of N-terminal Domain of Ribosomal Protein L9 (NTL9), G34dA
2HBB 2007-05-29 1.9 Crystal Structure of the N-terminal Domain of Ribosomal Protein L9 (NTL9)
1DIV 1997-01-11 2.6 RIBOSOMAL PROTEIN L9
487D 2000-04-10 7.5 SEVEN RIBOSOMAL PROTEINS FITTED TO A CRYO-ELECTRON MICROSCOPIC MAP OF THE LARGE 50S SUBUNIT AT 7.5 ANGSTROMS RESOLUTION

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
95.3 50S ribosomal protein L9 Q5KU74 RL9_GEOKA
96.6 50S ribosomal protein L9 A4ITV1 RL9_GEOTN
100.0 50S ribosomal protein L9 P02417 RL9_GEOSE