National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R35GM145341
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R35GM131901
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R35GM127086
米国
引用
ジャーナル: Nucleic Acids Res / 年: 2026 タイトル: Cryo-EM structure of a 95-base-pair double-stranded DNA minicircle at 5.3 Å resolution. 著者: Yukang Liu / Kyu-Yeon Lee / Yao He / Donggyun Kim / Hongjian Chang / Vadim Cherezov / Juli Feigon / Peter Z Qin / 要旨: Double-stranded DNA minicircles have been observed in a variety of biological settings and are also widely employed in biotechnology, therapeutic applications, and basic research. Here, we report a ...Double-stranded DNA minicircles have been observed in a variety of biological settings and are also widely employed in biotechnology, therapeutic applications, and basic research. Here, we report a cryo-EM structure of a 95-base-pair minicircle (dsMC95) at a 5.3 Å resolution. dsMC95 forms a closed ring as designed and no severe local duplex disruption is observed. The two DNA strands are fully resolved, with the major and minor grooves clearly distinguishable. Analysis reveals a nine-fold periodicity in the helical twist, which corresponds to approximately 10.56 base pairs per turn. Together with groove width analysis, the data indicate that dsMC95 maintains a B-DNA configuration. The dsMC95 ring exhibits modest in-plane ellipticity and small out-of-plane displacement, with outward-facing grooves widened and inward-facing ones compressed. The dsMC95 structure, which is the only free DNA cryo-EM structure with a resolution better than 6 Å to date, allows comparison to other structures to better understand DNA physical features such as bending. The findings advance our understanding of DNA structure under topological constraints and will inform studies of naturally occurring small circular DNA as well as the manipulation of DNA in nanotechnology applications.
履歴
登録
2026年5月5日
登録サイト: RCSB / 処理サイト: RCSB
改定 1.0
2026年9月30日
Provider: repository / タイプ: Initial release
改定 1.0
2026年9月30日
Data content type: EM metadata / Data content type: EM metadata / Provider: repository / タイプ: Initial release
分子量: 29709.711 Da / 分子数: 1 / 由来タイプ: 合成 詳細: The deposited coordinates represent a surrogate poly(dA) sequence instead of the actual DNA sequence 由来: (合成) synthetic construct (人工物)
#2: DNA鎖
DNA (95-MER)
分子量: 28853.314 Da / 分子数: 1 / 由来タイプ: 合成 詳細: The deposited coordinates represent a surrogate poly(dT) sequence instead of the actual DNA sequence. 由来: (合成) synthetic construct (人工物)
Has protein modification
N
配列の詳細
The coordinates contain an A-T only DNA model because the map does not support sequence-specific ...The coordinates contain an A-T only DNA model because the map does not support sequence-specific assignment. The actual DNA sequences are: CGATCAAGCCAGTGATAAGTGGAATGCCATGTGGTAAGATCGGTAGTCGTAGGCTCTCAA CTCGTATTCATCAACTGCATTCTGCCTACGACTAC and GTAGTCGTAGGCAGAATGCAGTTGATGAATACGAGTTGAGAGCCTACGACTACCGATCTT ACCACATGGCATTCCACTTATCACTGGCTTGATCG.
-
実験情報
-
実験
実験
手法: 電子顕微鏡法
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
-
試料調製
構成要素
ID
名称
タイプ
Entity ID
Parent-ID
由来
1
Synthetic 95-bp double-stranded DNA minicircle
COMPLEX
all
0
SYNTHETIC
2
DNA (95-MER)
COMPLEX
#1
1
SYNTHETIC
3
DNA (95-MER)
COMPLEX
#2
1
SYNTHETIC
分子量
ID
Entity assembly-ID
値 (°)
実験値
1
1
0.0587MDa
NO
2
1
0.0293MDa
NO
3
1
0.0294MDa
NO
由来(天然)
ID
Entity assembly-ID
生物種
Ncbi tax-ID
3
2
synthetic construct (人工物)
32630
4
3
synthetic construct (人工物)
32630
緩衝液
pH: 8 / 詳細: 20 mM Tris-HCl (pH 8.0) and 1 mM EDTA
緩衝液成分
ID
濃度
名称
Buffer-ID
1
20mM
Tris(hydroxymethyl)aminomethanehydrochloride
1
2
1mM
Ethylenediaminetetraaceticaciddisodiumsalt
1
試料
濃度: 0.7 mg/ml / 包埋: NO / シャドウイング: NO / 染色: NO / 凍結: YES