Structural basis for inhibition of an archaeal CRISPR–Cas type I-D large subunit by an anti-CRISPR protein
A hallmark of type I CRISPR–Cas systems is the presence of Cas3, which contains both the nuclease and helicase activities required for DNA cleavage during interference. In subtype I-D systems, however, the histidine-aspartate (HD) nuclease domain is encoded as part of a Cas10-like large effector com...
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Published in | Nature communications Vol. 11; no. 1; p. 5993 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
London
Nature Publishing Group UK
25.11.2020
Nature Publishing Group Nature Portfolio |
Subjects | |
Online Access | Get full text |
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Summary: | A hallmark of type I CRISPR–Cas systems is the presence of Cas3, which contains both the nuclease and helicase activities required for DNA cleavage during interference. In subtype I-D systems, however, the histidine-aspartate (HD) nuclease domain is encoded as part of a Cas10-like large effector complex subunit and the helicase activity in a separate Cas3’ subunit, but the functional and mechanistic consequences of this organisation are not currently understood. Here we show that the
Sulfolobus islandicus
type I-D Cas10d large subunit exhibits an unusual domain architecture consisting of a Cas3-like HD nuclease domain fused to a degenerate polymerase fold and a C-terminal domain structurally similar to Cas11. Crystal structures of Cas10d both in isolation and bound to
S. islandicus
rod-shaped virus 3 AcrID1 reveal that the anti-CRISPR protein sequesters the large subunit in a non-functional state unable to form a cleavage-competent effector complex. The architecture of Cas10d suggests that the type I-D effector complex is similar to those found in type III CRISPR–Cas systems and that this feature is specifically exploited by phages for anti-CRISPR defence.
In type I-D CRISPR–Cas systems, the nuclease and helicase activities are carried out by separate subunits. The crystal structure of
Sulfolobus islandicus
type I-D large subunit Cas10d, containing a nuclease domain, reveals unusual architecture. The structure of Cas10d in complex with anti-CRISPR protein AcrID1 suggests that the latter sequesters Cas10d in a nonfunctional state. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 2041-1723 2041-1723 |
DOI: | 10.1038/s41467-020-19847-x |