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データを開く
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基本情報
登録情報 | データベース: PDB / ID: 9b7y | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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タイトル | Cryo-EM structure of TetR regulator Mce3R from Mycobacterium tuberculosis bound to a DNA oligonucleotide | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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![]() | DNA BINDING PROTEIN/DNA / TetR-like repressor stress resistance / DNA BINDING PROTEIN-DNA complex | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
機能・相同性 | ![]() regulation of lipid metabolic process / lipid catabolic process / transcription cis-regulatory region binding / DNA-binding transcription factor activity / negative regulation of DNA-templated transcription / regulation of DNA-templated transcription / DNA binding 類似検索 - 分子機能 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
生物種 | ![]() | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
手法 | 電子顕微鏡法 / 単粒子再構成法 / クライオ電子顕微鏡法 / 解像度: 2.51 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
![]() | Panagoda, N. / Sampson, N. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
資金援助 | ![]()
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![]() | ![]() タイトル: Mce3R TetR-like Repressor Forms an Asymmetric Four-Helix Bundle and Binds a Nonpalindrome Sequence†. 著者: Navanjalee T Panagoda / Gábor Balázsi / Nicole S Sampson / ![]() 要旨: (), the causative agent of tuberculosis, is a major global health concern. TetR family repressors (TFRs) are important for 's adaptation to the human host environment. Our study focuses on one ... (), the causative agent of tuberculosis, is a major global health concern. TetR family repressors (TFRs) are important for 's adaptation to the human host environment. Our study focuses on one notable repressor, Mce3R, composed of an unusual double TFR motif. Mce3R-regulated genes encode enzymes implicated in cholesterol metabolism, resistance against reactive oxygen species, and lipid transport activities important for survival and persistence in the host and for the cellular activity of a 6-azasteroid derivative. Here, we present the structure of Mce3R bound to its DNA operator, unveiling a unique asymmetric assembly previously unreported. We obtained a candidate DNA-binding motif through MEME motif analysis, comparing intergenic regions of orthologues and identifying nonpalindromic regions conserved between orthologues. Using an electrophoretic mobility shift assay (EMSA), we confirmed that Mce3R binds to a 123-bp sequence that includes the predicted motif. Using scrambled DNA and DNA oligonucleotides of varying lengths with sequences from the upstream region of the () operon, we elucidated the operator region to be composed of two Mce3R binding sites, each a 25-bp asymmetric sequence separated by 53 bp. Mce3R binds with a higher affinity to the downstream site with a of 2.4 ± 0.7 nM. The cryo-EM structure of Mce3R bound to the 123-bp sequence was refined to a resolution of 2.51 Å. Each Mce3R monomer comprises 21 α-helices (α1-α21) folded into an asymmetric TFR-like structure with a core asymmetric four-helix bundle. This complex has two nonidentical HTH motifs and a single ligand-binding domain. The two nonidentical HTHs from each TFR bind within the high-affinity, nonpalindromic operator motif, with Arg53 and Lys262 inserted into the major groove. Site-directed mutagenesis of Arg53 to alanine abrogated DNA binding, validating the Mce3R/DNA structure obtained. Among 811,645 particles, 63% were Mce3R homodimer bound to two duplex oligonucleotides. Mce3R homodimerizes primarily through α15, and each monomer binds to an identical site in the DNA duplex oligonucleotide. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
履歴 |
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構造の表示
構造ビューア | 分子: ![]() ![]() |
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ダウンロードとリンク
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ダウンロード
PDBx/mmCIF形式 | ![]() | 223.2 KB | 表示 | ![]() |
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PDB形式 | ![]() | 169.1 KB | 表示 | ![]() |
PDBx/mmJSON形式 | ![]() | ツリー表示 | ![]() | |
その他 | ![]() |
-検証レポート
アーカイブディレクトリ | ![]() ![]() | HTTPS FTP |
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-関連構造データ
関連構造データ | ![]() 44328MC M: このデータのモデリングに利用したマップデータ C: 同じ文献を引用 ( |
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類似構造データ | 類似検索 - 機能・相同性 ![]() |
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リンク
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集合体
登録構造単位 | ![]()
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要素
#1: タンパク質 | 分子量: 44400.602 Da / 分子数: 2 / 由来タイプ: 組換発現 由来: (組換発現) ![]() 遺伝子: mce3R, Rv1963c / 発現宿主: ![]() ![]() #2: DNA鎖 | 分子量: 37845.172 Da / 分子数: 2 / 由来タイプ: 組換発現 由来: (組換発現) ![]() 発現宿主: ![]() ![]() #3: DNA鎖 | 分子量: 38063.328 Da / 分子数: 2 / 由来タイプ: 組換発現 由来: (組換発現) ![]() 発現宿主: ![]() ![]() Has protein modification | N | |
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-実験情報
-実験
実験 | 手法: 電子顕微鏡法 |
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EM実験 | 試料の集合状態: PARTICLE / 3次元再構成法: 単粒子再構成法 |
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試料調製
構成要素 | 名称: TetR regulator Mce3R from Mycobacterium tuberculosis bound to a DNA oligonucleotide タイプ: COMPLEX 詳細: Protein was prepared from a maltose-binding protein fusion construct and proteolytic cleavage with Tev protease. Entity ID: all / 由来: RECOMBINANT |
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分子量 | 実験値: NO |
由来(天然) | 生物種: ![]() |
由来(組換発現) | 生物種: ![]() ![]() |
緩衝液 | pH: 7.5 |
試料 | 濃度: 1 mg/ml / 包埋: NO / シャドウイング: NO / 染色: NO / 凍結: YES |
急速凍結 | 凍結剤: NITROGEN |
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電子顕微鏡撮影
実験機器 | ![]() モデル: Titan Krios / 画像提供: FEI Company |
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顕微鏡 | モデル: FEI TITAN KRIOS |
電子銃 | 電子線源: ![]() |
電子レンズ | モード: BRIGHT FIELD / 最大 デフォーカス(公称値): 2200 nm / 最小 デフォーカス(公称値): 800 nm |
撮影 | 電子線照射量: 55 e/Å2 フィルム・検出器のモデル: FEI FALCON IV (4k x 4k) |
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解析
EMソフトウェア | 名称: PHENIX / カテゴリ: モデル精密化 |
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CTF補正 | タイプ: PHASE FLIPPING AND AMPLITUDE CORRECTION |
3次元再構成 | 解像度: 2.51 Å / 解像度の算出法: FSC 0.143 CUT-OFF / 粒子像の数: 135814 / 対称性のタイプ: POINT |