Structure of Csx1-cOA₄ complex reveals the basis of RNA decay in Type III-B CRISPR-Cas

TY - JOUR

T1 - Structure of Csx1-cOA4 complex reveals the basis of RNA decay in Type III-B CRISPR-Cas

AU - Molina, Rafael

AU - Stella, Stefano

AU - Feng, Mingxia

AU - Sofos, Nicholas

AU - Jauniskis, Vykintas

AU - Pozdnyakova, Irina

AU - López-Méndez, Blanca

AU - She, Qunxin

AU - Montoya, Guillermo

PY - 2019/12/1

Y1 - 2019/12/1

N2 - Type III CRISPR-Cas multisubunit complexes cleave ssRNA and ssDNA. These activities promote the generation of cyclic oligoadenylate (cOA), which activates associated CRISPR-Cas RNases from the Csm/Csx families, triggering a massive RNA decay to provide immunity from genetic invaders. Here we present the structure of Sulfolobus islandicus (Sis) Csx1-cOA4 complex revealing the allosteric activation of its RNase activity. SisCsx1 is a hexamer built by a trimer of dimers. Each dimer forms a cOA4 binding site and a ssRNA catalytic pocket. cOA4 undergoes a conformational change upon binding in the second messenger binding site activating ssRNA degradation in the catalytic pockets. Activation is transmitted in an allosteric manner through an intermediate HTH domain, which joins the cOA4 and catalytic sites. The RNase functions in a sequential cooperative fashion, hydrolyzing phosphodiester bonds in 5'-C-C-3'. The degradation of cOA4 by Ring nucleases deactivates SisCsx1, suggesting that this enzyme could be employed in biotechnological applications.

AB - Type III CRISPR-Cas multisubunit complexes cleave ssRNA and ssDNA. These activities promote the generation of cyclic oligoadenylate (cOA), which activates associated CRISPR-Cas RNases from the Csm/Csx families, triggering a massive RNA decay to provide immunity from genetic invaders. Here we present the structure of Sulfolobus islandicus (Sis) Csx1-cOA4 complex revealing the allosteric activation of its RNase activity. SisCsx1 is a hexamer built by a trimer of dimers. Each dimer forms a cOA4 binding site and a ssRNA catalytic pocket. cOA4 undergoes a conformational change upon binding in the second messenger binding site activating ssRNA degradation in the catalytic pockets. Activation is transmitted in an allosteric manner through an intermediate HTH domain, which joins the cOA4 and catalytic sites. The RNase functions in a sequential cooperative fashion, hydrolyzing phosphodiester bonds in 5'-C-C-3'. The degradation of cOA4 by Ring nucleases deactivates SisCsx1, suggesting that this enzyme could be employed in biotechnological applications.

U2 - 10.1038/s41467-019-12244-z

DO - 10.1038/s41467-019-12244-z

M3 - Journal article

C2 - 31541109

SN - 2041-1723

VL - 10

JO - Nature Communications

JF - Nature Communications

M1 - 4302

ER -