3HRT

Crystal Structure of ScaR with bound Cd2+

3HRT の概要

• エントリーDOI: 10.2210/pdb3hrt/pdb
• 関連するPDBエントリー: 3HRS 3HRU
• 分子名称: Metalloregulator ScaR, SULFATE ION, CADMIUM ION (3 entities in total)
• 機能のキーワード: dtxr/mntr family member, transcription
• 由来する生物種: Streptococcus gordonii
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 49819.73

構造登録者

Stoll, K.E.,Draper, W.E.,Kliegman, J.I.,Golynskiy, M.V.,Brew-Appiah, R.A.T.,Brown, H.K.,Breyer, W.A.,Jakubovics, N.S.,Jenkinson, H.F.,Brennan, R.B.,Cohen, S.M.,Glasfeld, A. (登録日: 2009-06-09, 公開日: 2009-06-23, 最終更新日: 2023-09-06)

主引用文献

Stoll, K.E.,Draper, W.E.,Kliegman, J.I.,Golynskiy, M.V.,Brew-Appiah, R.A.,Phillips, R.K.,Brown, H.K.,Breyer, W.A.,Jakubovics, N.S.,Jenkinson, H.F.,Brennan, R.G.,Cohen, S.M.,Glasfeld, A.
Characterization and structure of the manganese-responsive transcriptional regulator ScaR.
Biochemistry, 48:10308-10320, 2009

PubMed Abstract: The streptococcal coaggregation regulator (ScaR) of Streptococcus gordonii is a manganese-dependent transcriptional regulator. When intracellular manganese concentrations become elevated, ScaR represses transcription of the scaCBA operon, which encodes a manganese uptake transporter. A member of the DtxR/MntR family of metalloregulators, ScaR shares sequence similarity with other family members, and many metal-binding residues are conserved. Here, we show that ScaR is an active dimer, with two dimers binding the 46 base pair scaC operator. Each ScaR subunit binds two manganese ions, and the protein is activated by a variety of other metal ions, including Cd(2+), Co(2+), and Ni(2+) but not Zn(2+). The crystal structure of apo-ScaR reveals a tertiary and quaternary structure similar to its homologue, the iron-responsive regulator DtxR. While each DtxR subunit binds a metal ion in two sites, labeled primary and ancillary, crystal structures of ScaR determined in the presence of Cd(2+) and Zn(2+) show only a single occupied metal-binding site that is novel to ScaR. The site analogous to the primary site in DtxR is unoccupied, and the ancillary site is absent from ScaR. Instead, metal ions bind to ScaR at a site labeled "secondary", which is composed of Glu80, Cys123, His125, and Asp160 and lies roughly 5 A away from where the ancillary site would be predicted to exist. This difference suggests that ScaR and its closely related homologues are activated by a mechanism distinct from that of either DtxR or MntR.

PubMed: 19795834
DOI: 10.1021/bi900980g

実験手法

X-RAY DIFFRACTION (2.8 Å)