National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
P01GM051487
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
F32GM122334
米国
Life Sciences Research Foundation
米国
引用
ジャーナル: Nat Commun / 年: 2019 タイトル: Target preference of Type III-A CRISPR-Cas complexes at the transcription bubble. 著者: Tina Y Liu / Jun-Jie Liu / Abhishek J Aditham / Eva Nogales / Jennifer A Doudna / 要旨: Type III-A CRISPR-Cas systems are prokaryotic RNA-guided adaptive immune systems that use a protein-RNA complex, Csm, for transcription-dependent immunity against foreign DNA. Csm can cleave RNA and ...Type III-A CRISPR-Cas systems are prokaryotic RNA-guided adaptive immune systems that use a protein-RNA complex, Csm, for transcription-dependent immunity against foreign DNA. Csm can cleave RNA and single-stranded DNA (ssDNA), but whether it targets one or both nucleic acids during transcription elongation is unknown. Here, we show that binding of a Thermus thermophilus (T. thermophilus) Csm (TthCsm) to a nascent transcript in a transcription elongation complex (TEC) promotes tethering but not direct contact of TthCsm with RNA polymerase (RNAP). Biochemical experiments show that both TthCsm and Staphylococcus epidermidis (S. epidermidis) Csm (SepCsm) cleave RNA transcripts, but not ssDNA, at the transcription bubble. Taken together, these results suggest that Type III systems primarily target transcripts, instead of unwound ssDNA in TECs, for immunity against double-stranded DNA (dsDNA) phages and plasmids. This reveals similarities between Csm and eukaryotic RNA interference, which also uses RNA-guided RNA targeting to silence actively transcribed genes.
ダウンロード / ファイル: emd_0455.map.gz / 形式: CCP4 / 大きさ: 8 MB / タイプ: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
注釈
Csm-RNAP
ボクセルのサイズ
X=Y=Z: 4.36 Å
密度
表面レベル
登録者による: 0.03 / ムービー #1: 0.03
最小 - 最大
-0.03912864 - 0.112419434
平均 (標準偏差)
0.0001628129 (±0.006225997)
対称性
空間群: 1
詳細
EMDB XML:
マップ形状
Axis order
X
Y
Z
Origin
-64
-64
-64
サイズ
128
128
128
Spacing
128
128
128
セル
A=B=C: 558.08 Å α=β=γ: 90.0 °
CCP4マップ ヘッダ情報:
mode
Image stored as Reals
Å/pix. X/Y/Z
4.36
4.36
4.36
M x/y/z
128
128
128
origin x/y/z
0.000
0.000
0.000
length x/y/z
558.080
558.080
558.080
α/β/γ
90.000
90.000
90.000
MAP C/R/S
1
2
3
start NC/NR/NS
-64
-64
-64
NC/NR/NS
128
128
128
D min/max/mean
-0.039
0.112
0.000
-
添付データ
-
試料の構成要素
-
全体 : Complex of Thermus thermophilus Csm with the Thermus thermophilus...
全体
名称: Complex of Thermus thermophilus Csm with the Thermus thermophilus transcription elongation complex
要素
複合体: Complex of Thermus thermophilus Csm with the Thermus thermophilus transcription elongation complex
-
超分子 #1: Complex of Thermus thermophilus Csm with the Thermus thermophilus...
超分子
名称: Complex of Thermus thermophilus Csm with the Thermus thermophilus transcription elongation complex タイプ: complex / ID: 1 / 親要素: 0 詳細: T. thermophilus Csm was recombinantly expressed in E. coli, and T. thermophilus RNA polymerase was isolated from the natural source.