English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Biochemical analysis of the Cas6-1 RNA endonuclease associated with the subtype I-D CRISPR-Cas system in Synechocystis sp. PCC 6803.

MPS-Authors
/persons/resource/persons77736

Benda,  Christian
Conti, Elena / Structural Cell Biology, Max Planck Institute of Biochemistry, Max Planck Society;

Locator
There are no locators available
Fulltext (public)
There are no public fulltexts available
Supplementary Material (public)
There is no public supplementary material available
Citation

Jesser, R., Behler, J., Benda, C., Reimann, V., & Hess, W. R. (2018). Biochemical analysis of the Cas6-1 RNA endonuclease associated with the subtype I-D CRISPR-Cas system in Synechocystis sp. PCC 6803. RNA Biology, 481-491. doi:10.1080/15476286.2018.1447742.


Cite as: http://hdl.handle.net/21.11116/0000-0003-10AB-A
Abstract
Specialized RNA endonucleases are critical for efficient activity of the CRISPR-Cas defense mechanisms against invading DNA or RNA. Cas6-type enzymes are the RNA endonucleases in many type I and type III CRISPR-Cas systems. These enzymes are diverse and critical residues involved in the recognition and cleavage of RNA substrates are not universally conserved. Cas6 endonucleases associated with the CRISPR-Cas subtypes I-A, I-B, I-C, I-E and I-F, as well as III-B have been studied from three archaea and four bacteria thus far. However, until now information about subtype I-D specific Cas6 endonucleases has remained scarce. Here, we report the biochemical analysis of Cas6-1, which is specific for the crRNA maturation from the subtype I-D CRISPR-Cas system of Synechocystis sp. PCC 6803. Assays of turnover kinetics suggest a single turnover mechanism for Cas6-1. The mutation of conserved amino acids R29A, H32A-S33A and H51A revealed these as essential, whereas the parallel mutation of R175A-R176A led to a pronounced and the K155A mutation to a slight reduction in enzymatic activity. In contrast, the mutations R67A, R81A and K231A left the enzymatic activity unchanged. These results are in accordance with the predominant role of histidine residues in the active site and of positively charged residues in RNA binding. Nevertheless, the protein-RNA interaction site seems to differ from other known systems, since imidazole could not restore the mutated histidine site.