Mutations of surface residues in Anabaena vegetative and heterocyst ferredoxin that affect thermodynamic stability as determined by guanidine hydrochloride denaturation.


Abstract

The stability properties of oxidized wild-type (wt) and site-directed mutants in surface residues of vegetative (Vfd) and heterocyst (Hfd) ferredoxins from Anabaena 7120 have been characterized by guanidine hydrochloride (Gdn-HCl) denaturation. For Vfd it was found that mutants E95K, E94Q, F65Y, F65W, and T48A are quite similar to wt in stability. E94K is somewhat less stable, whereas E94D, F65A, F65I, R42A, and R42H are substantially less stable than wt. R42H is a substitution found in all Hfds, and NMR comparison of the Anabaena 7120 Vfd and Hfd showed the latter to be much less stable on the basis of hydrogen exchange rates (Chae YK, Abildgaard F, Mooberry ES, Markley JL, 1994, Biochemistry 33:3287-3295); we also find this to be true with respect to Gdn-HCl denaturation. Strikingly, the Hfd mutant H42R is more stable than the wt Hfd by precisely the amount of stability lost in Vfd upon mutating R42 to H (2.0 kcal/mol). On the basis of comparison of the X-ray crystal structures of wt Anabaena Vfd and Hfd, the decreased stabilities of F65A and F65I can be ascribed to increased solvent exposure of interior hydrophobic groups. In the case of Vfd mutants E94K and E94D, the decreased stabilities may result from disruption of a hydrogen bond between the E94 and S47 side chains. The instability of the R42 mutants is also most probably due to decreased hydrogen bonding capabilities.(ABSTRACT TRUNCATED AT 250 WORDS) Study holds ProTherm entries: 7293, 7294, 7295, 7296, 7297, 7298, 7299, 7300, 7301, 7302, 7303, 7304, 7305, 7306 Extra Details: Vfd : Anabaena 7120 vegetative ferredoxin

Submission Details

ID: 9msTuUJ94

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:33 p.m.

Version: 1

Publication Details
Hurley JK;Caffrey MS;Markley JL;Cheng H;Xia B;Chae YK;Holden HM;Tollin G,Protein Sci. (1995) Mutations of surface residues in Anabaena vegetative and heterocyst ferredoxin that affect thermodynamic stability as determined by guanidine hydrochloride denaturation. PMID:7773177
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
1FRD 1993-04-14T00:00:00+0000 1.7 MOLECULAR STRUCTURE OF THE OXIDIZED, RECOMBINANT, HETEROCYST (2FE-2S) FERREDOXIN FROM ANABAENA 7120 DETERMINED TO 1.7 ANGSTROMS RESOLUTION
1FLV 1992-07-02T00:00:00+0000 2.0 STRUCTURE OF THE OXIDIZED LONG CHAIN FLAVODOXIN FROM ANABAENA 7120 AT 2 ANGSTROMS RESOLUTION
1RCF 1994-10-31T00:00:00+0000 1.4 STRUCTURE OF THE TRIGONAL FORM OF RECOMBINANT OXIDIZED FLAVODOXIN FROM ANABAENA 7120 AT 1.40 ANGSTROMS RESOLUTION
1CZP 1999-09-06T00:00:00+0000 1.17 ANABAENA PCC7119 [2FE-2S] FERREDOXIN IN THE REDUCED AND OXIXIZED STATE AT 1.17 A
1EWY 2000-04-28T00:00:00+0000 2.38 ANABAENA PCC7119 FERREDOXIN:FERREDOXIN-NADP+-REDUCTASE COMPLEX
1QT9 1999-07-01T00:00:00+0000 1.3 OXIDIZED [2FE-2S] FERREDOXIN FROM ANABAENA PCC7119
1FXA 1991-01-09T00:00:00+0000 2.5 CRYSTALLIZATION AND STRUCTURE DETERMINATION TO 2.5-ANGSTROMS RESOLUTION OF THE OXIDIZED [2FE-2S] FERREDOXIN ISOLATED FROM ANABAENA 7120
1J7A 2001-05-16T00:00:00+0000 1.8 STRUCTURE OF THE ANABAENA FERREDOXIN D68K MUTANT
1J7B 2001-05-16T00:00:00+0000 1.8 STRUCTURE OF THE ANABAENA FERREDOXIN MUTANT E94K
1J7C 2001-05-16T00:00:00+0000 1.8 STRUCTURE OF THE ANABAENA FERREDOXIN MUTANT E95K

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Flavodoxin P0A3E0 FLAV_NOSSO
100.0 Flavodoxin P0A3D9 FLAV_NOSS1
94.9 Ferredoxin-1 P00254 FER1_ANAVT
99.0 Ferredoxin-1 P00253 FER_DESMC
100.0 Ferredoxin-1 P0A3C8 FER1_NOSSO
100.0 Ferredoxin-1 P0A3C7 FER1_NOSS1
91.8 Ferredoxin, heterocyst P28610 FERH_MICDP
94.9 Ferredoxin, heterocyst P46046 FERH_ANAVT
100.0 Ferredoxin, heterocyst P11053 FERH_NOSS1