Dataset Information

Orthogonal CRISPR-associated transposases for parallel and multiplexed chromosomal integration.

ABSTRACT: Cell engineering is commonly limited to the serial manipulation of a single gene or locus. The recently discovered CRISPR-associated transposases (CASTs) could manipulate multiple sets of genes to achieve predetermined cell diversity, with orthogonal CASTs being able to manipulate them in parallel. Here, a novel CAST from Pseudoalteromonas translucida KMM520 (PtrCAST) was characterized without a protospacer adjacent motif (PAM) preference which can achieve a high insertion efficiency for larger cargo and multiplexed transposition and tolerate mismatches out of 4-nucleotide seed sequence. More importantly, PtrCAST operates orthogonally with CAST from Vibrio cholerae Tn6677 (VchCAST), though both belonging to type I-F3. The two CASTs were exclusively active on their respective mini-Tn substrate with their respective crRNAs that target the corresponding 5 and 2 loci in one Escherichia coli cell. The multiplexed orthogonal MUCICAT (MUlticopy Chromosomal Integration using CRISPR-Associated Transposases) is a powerful tool for cell programming and appears promising with applications in synthetic biology.

SUBMITTER: Yang S

PROVIDER: S-EPMC8464060 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Orthogonal CRISPR-associated transposases for parallel and multiplexed chromosomal integration.

Yang Siqi S Zhang Yiwen Y Xu Jiaqi J Zhang Jiao J Zhang Jieze J Yang Junjie J Jiang Yu Y Yang Sheng S

Nucleic acids research 20210901 17

Cell engineering is commonly limited to the serial manipulation of a single gene or locus. The recently discovered CRISPR-associated transposases (CASTs) could manipulate multiple sets of genes to achieve predetermined cell diversity, with orthogonal CASTs being able to manipulate them in parallel. Here, a novel CAST from Pseudoalteromonas translucida KMM520 (PtrCAST) was characterized without a protospacer adjacent motif (PAM) preference which can achieve a high insertion efficiency for larger ...[more]

PMID: 34478496

Similar Datasets

Project description:Unlike canonical CRISPR-Cas systems that rely on RNA-guided nucleases for target cleavage, CRISPR-associated transposases (CASTs) repurpose nuclease-deficient CRISPR effectors to facilitate RNA-guided transposition of large genetic payloads. Type V-K CASTs offer several potential upsides for genome engineering, due to their compact size, easy programmability, and unidirectional integration. However, these systems are substantially less accurate than type I-F CASTs, and the molecular basis for this difference has remained elusive. Here we reveal that type V-K CASTs undergo two distinct mobilization pathways with remarkably different specificities: RNA-dependent and RNA-independent transposition. Whereas RNA-dependent transposition relies on Cas12k for accurate target selection, RNA-independent integration events are untargeted and primarily driven by the local availability of TnsC filaments. The cryo-EM structure of the untargeted complex reveals a TnsB-TnsC-TniQ transpososome that encompasses two turns of a TnsC filament and otherwise resembles major architectural aspects of the Cas12k-containing transpososome. Using single-molecule experiments and genome-wide meta-analyses, we found that AT-rich sites are preferred substrates for untargeted transposition and that the TnsB transposase also imparts local specificity, which collectively determine the precise insertion site. Knowledge of these motifs allowed us to direct untargeted transposition events to specific hotspot regions of a plasmid. Finally, by exploiting TnsB's preference for on-target integration and modulating the availability of TnsC, we suppressed RNA-independent transposition events and increased type V-K CAST specificity up to 98.1%, without compromising the efficiency of on-target integration. Collectively, our results reveal the importance of dissecting target site selection mechanisms and highlight new opportunities to leverage CAST systems for accurate, kilobase-scale genome engineering applications.

Dataset Information

Orthogonal CRISPR-associated transposases for parallel and multiplexed chromosomal integration.

Publications

Orthogonal CRISPR-associated transposases for parallel and multiplexed chromosomal integration.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets