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-Structure paper
タイトル | Structure of the TnsB transposase-DNA complex of type V-K CRISPR-associated transposon. |
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ジャーナル・号・ページ | Nat Commun, Vol. 13, Issue 1, Page 5792, Year 2022 |
掲載日 | 2022年10月2日 |
著者 | Francisco Tenjo-Castaño / Nicholas Sofos / Blanca López-Méndez / Luisa S Stutzke / Anders Fuglsang / Stefano Stella / Guillermo Montoya / |
PubMed 要旨 | CRISPR-associated transposons (CASTs) are mobile genetic elements that co-opted CRISPR-Cas systems for RNA-guided transposition. Here we present the 2.4 Å cryo-EM structure of the Scytonema ...CRISPR-associated transposons (CASTs) are mobile genetic elements that co-opted CRISPR-Cas systems for RNA-guided transposition. Here we present the 2.4 Å cryo-EM structure of the Scytonema hofmannii (sh) TnsB transposase from Type V-K CAST, bound to the strand transfer DNA. The strand transfer complex displays an intertwined pseudo-symmetrical architecture. Two protomers involved in strand transfer display a catalytically competent active site composed by DDE residues, while other two, which play a key structural role, show active sites where the catalytic residues are not properly positioned for phosphodiester hydrolysis. Transposon end recognition is accomplished by the NTD1/2 helical domains. A singular in trans association of NTD1 domains of the catalytically competent subunits with the inactive DDE domains reinforces the assembly. Collectively, the structural features suggest that catalysis is coupled to protein-DNA assembly to secure proper DNA integration. DNA binding residue mutants reveal that lack of specificity decreases activity, but it could increase transposition in some cases. Our structure sheds light on the strand transfer reaction of DDE transposases and offers new insights into CAST transposition. |
リンク | Nat Commun / PubMed:36184667 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 2.46 - 11.2 Å |
構造データ | EMDB-15294, PDB-8aa5: EMDB-15344: Type V-K CAST TnsB bound to LTR-SR |
化合物 | ChemComp-HOH: |
由来 |
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キーワード | DNA BINDING PROTEIN / Transposase / complex / CRISPR / transposition / DNA cleavage / ligation |