Extended Data Fig. 10: The CRISPR array from the CRISPR-Cas9 system native to Alkalihalobacillus pseudalcaliphilus DSM 8725.
From: Spacer prioritization in CRISPR–Cas9 immunity is enabled by the leader RNA
The system falls within the II-C subtype. Accession #: LFJO01000002.1. a, Array sequence and context within the CRISPR-Cas9 system. The sequence begins immediately downstream of the AB990_04425 gene unrelated to the CRISPR-Cas9 system and ends after the last repeat of the CRISPR2 array. Repeats are in gray, spacers match the corresponding color in the cartoon, and mutations to the consensus repeat are shown in red. The underlined sequence denotes the upstream region used for the folding predictions for the CRISPR1 array. The transcriptional start sites for both arrays are unknown, although there is a clear Rho-independent terminator downstream of each array. The promoters driving expression of the cas genes, the CRISPR arrays, or the tracrRNA have not been mapped. The predicted direction of transcription for the tracrRNA and CRISPR array are indicated with black arrows. b, tracrRNA sequence and context within the CRISPR-Cas9 system. The sequence begins ~2.7 kb upstream of the AB990_04405 gene unrelated to the CRISPR-Cas9 system and ends immediately upstream of cas9. The sequence in orange corresponds to the putative tracrRNA used in the folding predictions. c, Predicted stem-loop between the first repeat and upstream region for the CRISPR1 array. The predicted stem-loop is part of the minimal-free energy structure and reflects base-pairing probabilities principally between 90% and 100%. Pairing between the second repeat and the tracrRNA is provided as a basis of comparison. The tracrRNA ends with a canonical Rho-independent terminator.
