Core mutants of the immunoglobulin binding domain of streptococcal protein G: stability and structural integrity.


Abstract

A library of core mutants of the GB1 domain of streptococcal protein G was created, and the structure and stability of selected members was assessed by 1H-15N heteronuclear correlation NMR spectroscopy and fluorescence. All mutants comprised changes in beta-sheet residues, with sidechains at positions 5 (Leu), 7 (Leu), 52 (Phe) and 54 (Val) forming the beta-sheet side of the sheet-helix core interface. A solvent exposed position Ile-6 was chosen as a control. Randomization of bases at codon positions 1 and 3 with thymine at position 2 introduces five possible hydrophobic amino acids, namely Leu, Val, Ile, Phe, and Met. The distribution of encoded amino acids at all five positions is approximately as expected theoretically and indicates that no major bias was introduced towards particular residues. The overall structural integrity of several mutants, as assessed by NMR, ranges from very close to wild type to fully unfolded. Interestingly, the stability of the mutants is not strictly correlated with the number of changes or residue volume. Study holds ProTherm entries: 9794, 9795, 9796, 9797, 9798, 9799, 9800 Extra Details: protein G; B1 domain; core mutant; library; protein design;,structure; stability

Submission Details

ID: EbwZCtP7

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:38 p.m.

Version: 1

Publication Details
Gronenborn AM;Frank MK;Clore GM,FEBS Lett. (1996) Core mutants of the immunoglobulin binding domain of streptococcal protein G: stability and structural integrity. PMID:8977129
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 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