Folding mechanism of Pseudomonas aeruginosa cytochrome c551: role of electrostatic interactions on the hydrophobic collapse and transition state properties.


Abstract

We report on the folding kinetics of the small 82 residue cytochrome c551from Pseudomonas aeruginosa. The presence of two Trp residues (Trp56 and Trp77) allows the monitoring of fluorescence quenching on refolding in two different regions of the protein. A single His residue (the iron-coordinating His16) permits the study of refolding in the absence of miscoordination events. After identification of the kinetic traps (Pro isomerization and aggregation of denatured protein), overall refolding kinetics is described by two processes: (i) a burstphase collapse (faster than milliseconds) which we show to be a global event leading to a state whose compactness depends on the overall net charge; at the isoeletric pH (4.7), it is maximally compact, while above and below it is more expanded; and (ii) an exponential phase (in the millisecond time range) leading to the native protein via a transition state(s) possibly involving the formation of a specific salt bridge between Lys10 and Glu70, at the contact between the N and C-terminal helices. Comparison with the widely studied horse cytochrome c allows the discussion of similarities and differences in the folding of two proteins which have the same "fold" despite a very low degree of sequence homology (<30 %). Study holds ProTherm entries: 5500, 5501, 5502, 5503 Extra Details: folding kinetics; burstphase; transition state; pH effect

Submission Details

ID: KHqBH8nZ

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:30 p.m.

Version: 1

Publication Details
Travaglini-Allocatelli C;CutruzzolĂ  F;Bigotti MG;Staniforth RA;Brunori M,J. Mol. Biol. (1999) Folding mechanism of Pseudomonas aeruginosa cytochrome c551: role of electrostatic interactions on the hydrophobic collapse and transition state properties. PMID:10373379
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
1DVV 2000-11-29 SOLUTION STRUCTURE OF THE QUINTUPLE MUTANT OF CYTOCHROME C-551 FROM PSEUDOMONAS AERUGINOSA
2PAC 1993-10-31 SOLUTION STRUCTURE OF FE(II) CYTOCHROME C551 FROM PSEUDOMONAS AERUGINOSA AS DETERMINED BY TWO-DIMENSIONAL 1H NMR
5XEC 2017-08-09 1.1 Heterodimer constructed from PA cyt c551-HT cyt c552 and HT cyt c552-PA cyt c551 chimeric proteins
3X39 2015-04-22 1.5 Domain-swapped dimer of Pseudomonas aeruginosa cytochrome c551
5XED 2017-08-09 1.55 Heterodimer constructed from M61A PA cyt c551-HT cyt c552 and HT cyt c552-PA cyt c551 chimeric proteins
451C 1981-10-02 1.6 STRUCTURE OF CYTOCHROME C551 FROM P. AERUGINOSA REFINED AT 1.6 ANGSTROMS RESOLUTION AND COMPARISON OF THE TWO REDOX FORMS
351C 1981-10-02 1.6 STRUCTURE OF CYTOCHROME C551 FROM P. AERUGINOSA REFINED AT 1.6 ANGSTROMS RESOLUTION AND COMPARISON OF THE TWO REDOX FORMS
2EXV 2006-02-07 1.86 Crystal structure of the F7A mutant of the cytochrome c551 from Pseudomonas aeruginosa

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Cytochrome c-551 P00099 CY551_PSEAE