PXD047440

PXD047440 is an original dataset announced via ProteomeXchange.

Title	Control of a type III-Dv CRISPR-Cas system by the transcription factor RpaB and interaction of its transcribed leader with the DEAD-box RNA helicase CrhR
Description	CRISPR-Cas systems in bacteria and archaea provide powerful defense against phages and other foreign genetic elements. The principles of CRISPR-Cas activity are well understood, but less is known about how their expression is regulated. The cyanobacterium Synechocystis sp. PCC 6803 encodes three separate CRISPR-Cas systems. The expression of one of these, a type III-Dv system, responds to changes in environmental conditions such as nitrogen starvation or changing light intensities. Here, we found that the promoter of the respective six-gene cas operon is controlled by the light- and redox-responsive transcription factor RpaB. RpaB binds to an HLR1 motif 53 to 70 nt upstream of the transcriptional start site, leading to the activation of transcription at low light intensities. However, the strong promoter driving transcription of the cognate repeat-spacer array is not under RpaB control. Instead, we found the 125 nt transcribed leader to be bound by the redox-sensitive RNA helicase CrhR, and crosslinking coupled to mass spectrometry analysis revealed six residues specifically interacting with it. From these, L103, F104, H225, and C371 were predicted on the surface of a dimeric CrhR model. These results show that the expression of the CRISPR-Cas system is linked to the redox status of the photosynthetic cyanobacterial cell and that the elements involved are unique in that they act at two different levels. While RpaB affects transcription, CrhR engages with the transcribed leader at the post-transcriptional level. These results highlight the complex nature of the interrelationships between a CRISPR-Cas system and its host cell.
HostingRepository	PRIDE
AnnounceDate	2024-07-15
AnnouncementXML	Submission_2024-07-15_08:58:47.409.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Olexandr Dybkov
SpeciesList	scientific name: Synechocystis sp. (strain PCC 6803 / Kazusa); NCBI TaxID: 1111708;
ModificationList	No PTMs are included in the dataset
Instrument	Q Exactive HF

Revision	Datetime	Status	ChangeLog Entry
0	2023-12-01 04:20:35	ID requested
⏵ 1	2024-07-15 08:58:47	announced

10.1016/J.CELREP.2024.114485;

submitter keyword: cyanobacteria, CrhR DEAD-box RNA helicase, CRISPR leader, transcription factor RpaB,CRISPR-Cas systems, regulation of CRISPR-Cas gene expression

RNA structure

Olexandr Dybkov
contact affiliation	Bioanalytical Mass Spectrometry Group, Max Planck Institute for Multidisciplinary Sciences, Germany
contact email	odybkov@gwdg.de
lab head
Olexandr Dybkov
contact affiliation	Max Planck Institute for Multidisciplinary Sciences
contact email	odybkov@gwdg.de
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD047440
     1. Label: PRIDE project
     2. Name: Control of a type III-Dv CRISPR-Cas system by the transcription factor RpaB and interaction of its transcribed leader with the DEAD-box RNA helicase CrhR