Salt-bridges can stabilize but do not accelerate the folding of the homodimeric coiled-coil peptide GCN4-p1.


Abstract

Double mutant cycle analysis was employed to ascertain the role of intra- and interchain salt-bridges in the folding and stability of the dimeric coiled-coil peptide, GCN4-p1, the 33-residue leucine zipper domain of the transcriptional activator GCN4. Equilibrium circular dichroism studies of the urea-induced unfolding reaction at neutral pH revealed that both types of ionic interactions, localized primarily in the N-terminal portion of the molecule, enhance the stability of the native coiled-coil. By contrast, comparable stopped-flow circular dichroism studies indicate that the salt-bridge interactions, with one possible exception, are not well formed in the transition state for folding. Although the E22Q/R25A double mutant failed to fold, fragmentation studies suggest that the E22/R25 intramolecular salt-bridge may play a critical role in stabilizing C-terminal nascent helices that drive the association reaction. The remaining salt-bridges appear to stabilize the parallel-stranded coiled-coil architecture of GCN4-p1 only after the peptide traverses the rate-limiting, dimeric transition state. Study holds ProTherm entries: 17015, 17016, 17017, 17018, 17019, 17020, 17021, 17022, 17023, 17024, 17025, 17026, 17027, 17028, 17029 Extra Details: Pseudo wild type M2V. circular dichroism spectroscopy; electrostatics; ionic interactions; leucine zipper peptides; protein folding kinetics

Submission Details

ID: ZaCckz9Q

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:49 p.m.

Version: 1

Publication Details
Ibarra-Molero B;Zitzewitz JA;Matthews CR,J. Mol. Biol. (2004) Salt-bridges can stabilize but do not accelerate the folding of the homodimeric coiled-coil peptide GCN4-p1. PMID:15037063
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
1CE9 1999-03-18T00:00:00+0000 1.8 HELIX CAPPING IN THE GCN4 LEUCINE ZIPPER
1DGC 1993-07-15T00:00:00+0000 3.0 THE X-RAY STRUCTURE OF THE GCN4-BZIP BOUND TO ATF/CREB SITE DNA SHOWS THE COMPLEX DEPENDS ON DNA FLEXIBILITY
1FAV 2000-07-13T00:00:00+0000 3.0 THE STRUCTURE OF AN HIV-1 SPECIFIC CELL ENTRY INHIBITOR IN COMPLEX WITH THE HIV-1 GP41 TRIMERIC CORE
1FMH 2000-08-17T00:00:00+0000 0 NMR SOLUTION STRUCTURE OF A DESIGNED HETERODIMERIC LEUCINE ZIPPER
1FMH 2000-08-17T00:00:00+0000 0 NMR SOLUTION STRUCTURE OF A DESIGNED HETERODIMERIC LEUCINE ZIPPER
1GCL 1993-10-20T00:00:00+0000 2.1 GCN4 LEUCINE ZIPPER CORE MUTANT P-LI
1GCM 1995-04-25T00:00:00+0000 1.8 GCN4 LEUCINE ZIPPER CORE MUTANT P-LI
1GK6 2001-08-08T00:00:00+0000 1.9 Human vimentin coil 2B fragment linked to GCN4 leucine zipper (Z2B)
1GZL 2002-05-23T00:00:00+0000 1.8 Crystal structure of C14linkmid/IQN17: a cross-linked inhibitor of HIV-1 entry bound to the gp41 hydrophobic pocket
1IHQ 2001-04-19T00:00:00+0000 0 GLYTM1BZIP: A CHIMERIC PEPTIDE MODEL OF THE N-TERMINUS OF A RAT SHORT ALPHA TROPOMYOSIN WITH THE N-TERMINUS ENCODED BY EXON 1B

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 General control protein GCN4 P03069 GCN4_YEAST