1ZK7

Crystal Structure of Tn501 MerA

1ZK7 の概要

• エントリーDOI: 10.2210/pdb1zk7/pdb
• 関連するPDBエントリー: 1GER 3GRS
• 分子名称: Mercuric reductase, SULFATE ION, FLAVIN-ADENINE DINUCLEOTIDE, ... (5 entities in total)
• 機能のキーワード: mercuric ion reductase, oxidoreductase
• 由来する生物種: Pseudomonas aeruginosa
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 50575.83

構造登録者

Dong, A.,Ledwidge, R.,Patel, B.,Fiedler, D.,Falkowski, M.,Zelikova, J.,Summers, A.O.,Pai, E.F.,Miller, S.M. (登録日: 2005-05-02, 公開日: 2005-07-05, 最終更新日: 2024-10-30)

主引用文献

Ledwidge, R.,Patel, B.,Dong, A.,Fiedler, D.,Falkowski, M.,Zelikova, J.,Summers, A.O.,Pai, E.F.,Miller, S.M.
NmerA, the Metal Binding Domain of Mercuric Ion Reductase, Removes Hg(2+) from Proteins, Delivers It to the Catalytic Core, and Protects Cells under Glutathione-Depleted Conditions
Biochemistry, 44:11402-11416, 2005

PubMed Abstract: The ligand binding and catalytic properties of heavy metal ions have led to the evolution of metal ion-specific pathways for control of their intracellular trafficking and/or elimination. Small MW proteins/domains containing a GMTCXXC metal binding motif in a betaalphabetabetaalphabeta fold are common among proteins controlling the mobility of soft metal ions such as Cu(1+), Zn(2+), and Hg(2+), and the functions of several have been established. In bacterial mercuric ion reductases (MerA), which catalyze reduction of Hg(2+) to Hg(0) as a means of detoxification, one or two repeats of sequences with this fold are highly conserved as N-terminal domains (NmerA) of uncertain function. To simplify functional analysis of NmerA, we cloned and expressed the domain and catalytic core of Tn501 MerA as separate proteins. In this paper, we show Tn501 NmerA to be a stable, soluble protein that binds 1 Hg(2+)/domain and delivers it to the catalytic core at kinetically competent rates. Comparison of steady-state data for full-length versus catalytic core MerA using Hg(glutathione)(2) or Hg(thioredoxin) as substrate demonstrates that the NmerA domain does participate in acquisition and delivery of Hg(2+) to the catalytic core during the reduction catalyzed by full-length MerA, particularly when Hg(2+) is bound to a protein. Finally, comparison of growth curves for glutathione-depleted Escherichia coli expressing either catalytic core, full-length, or a combination of core plus NmerA shows an increased protection of cells against Hg(2+) in the media when NmerA is present, providing the first evidence of a functional role for this highly conserved domain.

PubMed: 16114877
DOI: 10.1021/bi050519d

実験手法

X-RAY DIFFRACTION (1.6 Å)