5HR3

Crystal structure of thioredoxin N106A mutant

Summary for 5HR3

• Entry DOI: 10.2210/pdb5hr3/pdb
• Related: 5HR0 5HR1 5HR2
• Descriptor: Thioredoxin, COPPER (II) ION, ETHANOL, ... (5 entities in total)
• Functional Keywords: thioredoxin, thiol redox-reactions, oxidoreductase
• Biological source: Escherichia coli
• Total number of polymer chains: 2
• Total formula weight: 23929.95

Authors

Noguera, M.E.,Vazquez, D.S.,Howard, E.I.,Cousido-Siah, A.,Mitschler, A.,Podjarny, A.,Santos, J. (deposition date: 2016-01-22, release date: 2017-02-22, Last modification date: 2024-10-23)

Primary citation

Noguera, M.E.,Vazquez, D.S.,Ferrer-Sueta, G.,Agudelo, W.A.,Howard, E.,Rasia, R.M.,Manta, B.,Cousido-Siah, A.,Mitschler, A.,Podjarny, A.,Santos, J.
Structural variability of E. coli thioredoxin captured in the crystal structures of single-point mutants.
Sci Rep, 7:42343-42343, 2017

PubMed Abstract: Thioredoxin is a ubiquitous small protein that catalyzes redox reactions of protein thiols. Additionally, thioredoxin from E. coli (EcTRX) is a widely-used model for structure-function studies. In a previous paper, we characterized several single-point mutants of the C-terminal helix (CTH) that alter global stability of EcTRX. However, spectroscopic signatures and enzymatic activity for some of these mutants were found essentially unaffected. A comprehensive structural characterization at the atomic level of these near-invariant mutants can provide detailed information about structural variability of EcTRX. We address this point through the determination of the crystal structures of four point-mutants, whose mutations occurs within or near the CTH, namely L94A, E101G, N106A and L107A. These structures are mostly unaffected compared with the wild-type variant. Notably, the E101G mutant presents a large region with two alternative traces for the backbone of the same chain. It represents a significant shift in backbone positions. Enzymatic activity measurements and conformational dynamics studies monitored by NMR and molecular dynamic simulations show that E101G mutation results in a small effect in the structural features of the protein. We hypothesize that these alternative conformations represent samples of the native-state ensemble of EcTRX, specifically the magnitude and location of conformational heterogeneity.

PubMed: 28181556
DOI: 10.1038/srep42343

Experimental method

X-RAY DIFFRACTION (1.101 Å)