A protospacer adjacent motif (PAM) is a 2–6-base pair DNA sequence immediately following the DNA sequence targeted by the Cas9 nuclease in the CRISPR bacterial adaptive immune system. [1] The PAM is a component of the invading virus or plasmid, but is not found in the bacterial host genome and hence is not a component of the bacterial CRISPR ...

The most commonly used Cas9 nuclease, derived from S. pyogenes, recognizes a PAM sequence of NGG that is found directly downstream of the target sequence in the genomic DNA, on the non-target strand. Recognition of the PAM by the Cas9 nuclease is thought to destabilize the adjacent sequence, allowing interrogation of the sequence by the crRNA ...

在 CRISPR-Cas9 基因编辑中，选择合适的 PAM （原间隔相邻基序）序列对于确保编辑效率和特异性至关重要。PAM序列是Cas9蛋白识别目标DNA的关键元件，决定了Cas9能否与目标位点结合并进行剪切。

2018年2月28日 · Here we use phage-assisted continuous evolution to evolve an expanded PAM Sp Cas9 variant (xCas9) that can recognize a broad range of PAM sequences including NG, GAA and GAT.

2014年7月27日 · Here we report a crystal structure of Streptococcus pyogenes Cas9 in complex with a single-molecule guide RNA and a target DNA containing a canonical 5′-NGG-3′ PAM. The structure reveals that...

2023年12月12日 · PAM sequences are an important factor to consider when designing your CRISPR-Cas9 experiment. This article answers your PAM-related questions, such as: what is a PAM sequence, how to identify a PAM sequence, and …

2020年5月18日 · To achieve efficient editing activity, we graft the PAM-interacting domain of SmacCas9 to its well-established ortholog from Streptococcus pyogenes (SpyCas9), and further engineer an increased...

2025年3月13日 · CRISPR-Cas9 技术在过去十年中彻底改变了基因组编辑领域，但目前的应用主要依赖于少数几种Cas9蛋白，特别是来自化脓性链球菌(SpyCas9)和金黄色葡萄球菌(SauCas9)的Cas9。. 这些Cas9的 PAM (原间隔序列邻近基序)要求限制了可编辑的基因组序列范围。 此外，金黄色葡萄球菌是人类病原体，可能引起预存免疫 ...

2022年11月3日 · CRISPR-Cas9-mediated genome editing depends on PAM recognition to initiate DNA unwinding. PAM mutations can abolish Cas9 binding and prohibit editing. Here, we identified a Cas9 from the thermophile Alicyclobacillus tengchongensis for which the PAM interaction can be robustly regulated by DNA topology.

2025年3月13日 · CRISPR-Cas9 系统：它是首个被开发用于基因组编辑的CRISPR-Cas系统，该系统在发挥作用时，Cas9蛋白与crRNA-tracrRNA（或直接称为sgRNA，其中tracrRNA对crRNA的成熟至关重要）组成活性核酸酶，这一复合物会先识别 PAM序列 （Cas9识别的PAM序列是NGG），然后PAM序列的近段将发生 ...