The structural stability of a protein is an important determinant of its proteolytic susceptibility in Escherichia coli.


Abstract

To investigate the relationship between the degradation rate of a protein in Escherichia coli and its thermal stability in vitro, we constructed a set of variants of the N-terminal domain of lambda repressor with a wide range of melting temperatures. Pulse-chase experiments showed that, within this set, the proteins that are most thermally stable have the longest intracellular half-lives and vice versa. Moreover, second-site mutations which act directly or indirectly to increase the thermodynamic stability of the native N-terminal domain were found to suppress the intracellular degradation of one of the unstable mutants. These data suggest that thermal stability is, indeed, a key determinant of the proteolytic susceptibility of this protein in the cell. It is not the sole determinant, however, as sequences at the extreme C terminus of the N-terminal domain can influence proteolytic sensitivity without affecting the stability of the native structure. We propose that the thermal stability of the N-terminal domain of lambda repressor is an important determinant of its proteolytic sensitivity because degradation proceeds primarily from the unfolded form and that sequence determinants within the unfolded chain influence whether the unfolded protein will be a good substrate for proteolytic enzymes. Study holds ProTherm entries: 5162, 5163, 5164, 5165 Extra Details: structural stability; proteolytic susceptibility;,N-terminal domain; proteolytic sensitivity; degradation

Submission Details

ID: gPgfQKMJ3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:28 p.m.

Version: 1

Publication Details
Parsell DA;Sauer RT,J. Biol. Chem. (1989) The structural stability of a protein is an important determinant of its proteolytic susceptibility in Escherichia coli. PMID:2651442
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
3KZ3 2010-02-23 1.64 A structure of a lambda repressor fragment mutant
5ZCA 2018-08-15 1.8 Crystal structure of lambda repressor (1-20) fused with maltose-binding protein
1LMB 1991-11-05 1.8 REFINED 1.8 ANGSTROM CRYSTAL STRUCTURE OF THE LAMBDA REPRESSOR-OPERATOR COMPLEX
1F39 2000-07-26 1.9 CRYSTAL STRUCTURE OF THE LAMBDA REPRESSOR C-TERMINAL DOMAIN
3WOA 2015-04-29 2.0 Crystal structure of lambda repressor (1-45) fused with maltose-binding protein
1LLI 1994-08-31 2.1 THE CRYSTAL STRUCTURE OF A MUTANT PROTEIN WITH ALTERED BUT IMPROVED HYDROPHOBIC CORE PACKING
1RIO 2004-01-27 2.3 Structure of bacteriophage lambda cI-NTD in complex with sigma-region4 of Thermus aquaticus bound to DNA
1KCA 2001-12-21 2.91 Crystal Structure of the lambda Repressor C-terminal Domain Octamer
1LRP 1989-01-09 3.2 COMPARISON OF THE STRUCTURES OF CRO AND LAMBDA REPRESSOR PROTEINS FROM BACTERIOPHAGE LAMBDA
3BDN 2008-04-15 3.91 Crystal Structure of the Lambda Repressor

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Repressor protein cI P03034 RPC1_LAMBD