Guide RNA and PAM recognition

The targeting mechanism that combines guide–DNA complementarity with protospacer-adjacent-motif recognition by Cas9. The bounded proposition retained by the canonical record is: The cited experiments show that guide sequence and adjacent motif requirements condition Cas9 binding and cleavage in the reconstructed system.

The applicable scope is The constructs, biological systems, protocols, assays, datasets, and comparisons reported in A programmable dual-RNA-guided DNA endonuclease in adaptive bacterial immunity. This definition must not be generalized beyond the cited source and exact record boundary.

The study reconstitutes RNA-programmed Cas9 cleavage in vitro and shows that a designed single-guide RNA can direct sequence-specific DNA cleavage adjacent to an appropriate motif. This is the source-bound technical context for the record; no uncited mechanism is added by the compiler.

Sequence recognition rules do not by themselves predict chromatin access, cellular activity, or every off-target interaction. The mechanism or method is therefore presented as one component of a larger system, not as evidence for every downstream outcome.

There is no universal effect estimate for this method; numerical results remain attached to the source experiment, biological system, assay, and analysis choices. The evidence maturity recorded here is single study, and the claim kind is empirical claim.

This candidate records one bounded source package. Independent replications and contradictory results must be compiled separately before evidence maturity is upgraded. An in-vitro nuclease mechanism does not establish editing efficiency, specificity, delivery, safety, or phenotype in cells or organisms. These qualifications travel with the claim whenever it is reused.

The inspected source supports exactly this: The study reconstitutes RNA-programmed Cas9 cleavage in vitro and shows that a designed single-guide RNA can direct sequence-specific DNA cleavage adjacent to an appropriate motif. It was read at Abstract; Figures 1–5; supplementary materials describing guide design and cleavage assays.

What remains unknown is everything outside that locator. Sequence recognition rules do not by themselves predict chromatin access, cellular activity, or every off-target interaction. No quantity, comparison, or downstream outcome is established here unless a separately scoped record measures it.

The bound source is “A programmable dual-RNA-guided DNA endonuclease in adaptive bacterial immunity” by Martin Jinek, Krzysztof Chylinski, Ines Fonfara, Michael Hauer, Jennifer A. Doudna, Emmanuelle Charpentier, published by Science on 2012-06-28; its declared stable identity is doi:10.1126/science.1225829.

The inspected-content locator is Abstract; Figures 1–5; supplementary materials describing guide design and cleavage assays. Reuse is limited to citation-with-paraphrase. Maha paraphrases the source-level result and links to the version of record; no article passage is reproduced. This metadata establishes source identity and inspection scope, not the truth of claims outside the cited locator.