6MOS

Structure of thioredoxin 1 from the thermophilic eubacterium Thermosipho africanus TCF52B

6MOS の概要

• エントリーDOI: 10.2210/pdb6mos/pdb
• 分子名称: Thioredoxin, TRIS(HYDROXYETHYL)AMINOMETHANE (3 entities in total)
• 機能のキーワード: thioredoxin, thermophile, thermosipho africanus, protein stability, catalysis, oxidoreductase
• 由来する生物種: Thermosipho africanus (strain TCF52B)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 14012.11

構造登録者

Sahtout, N.,Kuttiyatveetil, J.R.,Sanders, D.A.R. (登録日: 2018-10-04, 公開日: 2019-08-14, 最終更新日: 2024-11-20)

主引用文献

Sahtout, N.,Kuttiyatveetil, J.R.A.,Sanders, D.A.R.
Structure and function of the putative thioredoxin 1 from the thermophilic eubacterium Thermosipho africanus strain TCF52B.
Biochim Biophys Acta Proteins Proteom, 1867:426-433, 2019

PubMed Abstract: The thioredoxin system is a ubiquitous oxidoreductase system that consists of the enzyme thioredoxin reductase (TrxR), its cofactor nicotinamide adenine dinucleotide phosphate (NAD(P)H) and the protein thioredoxin (Trx). The system has been comprehensively studied from many organisms, such as Escherichia coli (E. coli); however, structural and functional analysis of this system from thermophilic bacteria has not been as extensive. In this study, Thermosipho africanus, a thermophilic eubacterium, Trx1 (TaTrx1) was successfully cloned, overexpressed and purified, to greater than 95% purity. Inspection of the amino acid sequence of TaTrx1 categorized the protein as a putative Trx. Its ability to reduce the interchain disulfides of insulin, in the presence of dithiothreitol, provided further evidence to suggest that it was a Trx. The three dimensional structure of the protein, determined using X-ray crystallography, provided additional evidence for this. The crystal structure was solved in space group P222 to 1.8 Ă resolution and showed the characteristic thioredoxin fold; four β-strands surrounded by three α-helices. The active site of TaTrx1 contained two cysteines that formed a disulfide bridge, and was structurally similar to the active site of EcTrx1. Further studies indicated that TaTrx1 was far more stable than Trx1 of E. coli (EcTrx1). The protein could withstand both higher temperatures and higher concentrations of guanidine hydrochloride before denaturing. Our studies have therefore identified a novel thermophilic putative Trx that structurally and functionally behaves like a Trx.

PubMed: 30716506
DOI: 10.1016/j.bbapap.2019.01.011

実験手法

X-RAY DIFFRACTION (1.80013732031 Å)