Structure and dynamics of an acid-denatured protein G mutant.


Abstract

NMR studies of protein denatured states provide insights into potential initiation sites for folding that may be too transient to be observed kinetically. We have characterized the structure and dynamics of the acid-denatured state of protein G by using a F30H mutant of G(B1) which is on the margin of stability. At 5 degrees C, F30H-G(B1) is greater than 95% folded at pH 7.0 and is greater than 95% unfolded at pH 4.0. This range of stability is useful because the denatured state can be examined under relatively mild conditions which are optimal for folding G(B1). We have assigned almost all backbone (15)N, H(N), and H(alpha) resonances in the acid-denatured state. Chemical shift, coupling constant, and NOE data indicate that the denatured state has considerably more residual structure when studied under these mild conditions than in the presence of chemical denaturants. The acid-denatured state populates nativelike conformations with both alpha-helical and beta-hairpin characteristics. To our knowledge, this is the first example of a denatured state with NOE and coupling constant evidence for beta-hairpin character. A number of non-native turn structures are also detected, particularly in the region corresponding to the beta1-beta2 hairpin of the folded state. Steady-state ¿(1)H-(15)N¿ NOE results demonstrate restricted backbone flexibility in more structured regions of the denatured protein. Overall, our studies suggest that regions of the helix, the beta3-beta4 hairpin, and the beta1-beta2 turn may serve as potential initiation sites for folding of G(B). Furthermore, residual structure in acid-denatured F30H-G(B1) is more extensive than in peptide fragments corresponding to the beta1-beta2, alpha-helix, and beta3-beta4 regions, suggesting additional medium-to-long-range interactions in the full-length polypeptide chain. Study holds ProTherm entries: 7902, 7903 Extra Details: protein denatured states; backbone flexibility; potential,initiation sites; long-range interactions

Submission Details

ID: khq8jkYv3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:35 p.m.

Version: 1

Publication Details
Sari N;Alexander P;Bryan PN;Orban J,Biochemistry (2000) Structure and dynamics of an acid-denatured protein G mutant. PMID:10653640
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
1EM7 2000-03-16T00:00:00+0000 2.0 HELIX VARIANT OF THE B1 DOMAIN FROM STREPTOCOCCAL PROTEIN G
1GB1 1991-05-15T00:00:00+0000 0 A NOVEL, HIGHLY STABLE FOLD OF THE IMMUNOGLOBULIN BINDING DOMAIN OF STREPTOCOCCAL PROTEIN G
1IGC 1994-08-05T00:00:00+0000 2.6 IGG1 FAB FRAGMENT (MOPC21) COMPLEX WITH DOMAIN III OF PROTEIN G FROM STREPTOCOCCUS
1IGD 1994-08-05T00:00:00+0000 1.1 THE THIRD IGG-BINDING DOMAIN FROM STREPTOCOCCAL PROTEIN G: AN ANALYSIS BY X-RAY CRYSTALLOGRAPHY OF THE STRUCTURE ALONE AND IN A COMPLEX WITH FAB
1LE3 2002-04-09T00:00:00+0000 0 NMR Structure of Tryptophan Zipper 4: A Stable Beta-Hairpin Peptide Based on the C-terminal Hairpin of the B1 Domain of Protein G
1MPE 2002-09-12T00:00:00+0000 0 Ensemble of 20 structures of the tetrameric mutant of the B1 domain of streptococcal protein G
1MVK 2002-09-25T00:00:00+0000 2.5 X-ray structure of the tetrameric mutant of the B1 domain of streptococcal protein G
1PGA 1993-11-23T00:00:00+0000 2.07 TWO CRYSTAL STRUCTURES OF THE B1 IMMUNOGLOBULIN-BINDING DOMAIN OF STREPTOCOCCAL PROTEIN G AND COMPARISON WITH NMR
1PGB 1993-11-23T00:00:00+0000 1.92 TWO CRYSTAL STRUCTURES OF THE B1 IMMUNOGLOBULIN-BINDING DOMAIN OF STREPTOCCOCAL PROTEIN G AND COMPARISON WITH NMR
1PGX 1992-04-03T00:00:00+0000 1.66 THE 1.66 ANGSTROMS X-RAY STRUCTURE OF THE B2 IMMUNOGLOBULIN-BINDING DOMAIN OF STREPTOCOCCAL PROTEIN G AND COMPARISON TO THE NMR STRUCTURE OF THE B1 DOMAIN

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Immunoglobulin G-binding protein G P06654 SPG1_STRSG
100.0 Immunoglobulin G-binding protein G P19909 SPG2_STRSG