Related Experiment Video
Updated: Jan 7, 2026
07:56
Genome Editing in Mammalian Cell Lines using CRISPR-Cas
Published on: April 11, 2019
23.0K
Streptococcus uberis Cas9-A Compact Type II-A Nuclease Recognizing a Unique PAM and Functional in Human Cells
Aleksandra Vasileva1, Marina Abramova1, Polina Selkova1
1Research Center of Nanobiotechnologies, Peter the Great Saint Petersburg Polytechnic University, Saint Petersburg, Russia.
The CRISPR Journal
|December 30, 2025
Summary
Researchers discovered SuCas9, a compact CRISPR-Cas9 genome editing tool. This novel enzyme from Streptococcus uberis recognizes a new PAM sequence and functions effectively in human cells, expanding gene editing possibilities.
Area of Science:
- Molecular Biology
- Genetics
- Biotechnology
Background:
- Type II CRISPR-Cas9 systems are widely used for genome engineering.
- Existing Cas9 enzymes are large and have specific protospacer adjacent motif (PAM) requirements.
- There is a need for more compact Cas9 variants with novel PAM specificities.
Purpose of the Study:
- To identify and characterize a novel, compact Cas9 nuclease.
- To evaluate its activity and PAM specificity for genome editing applications.
Main Methods:
- Bioinformatic identification of Cas9 orthologs.
- Biochemical assays for DNA cleavage activity.
- Functional validation in human cell lines.
Main Results:
- A compact Cas9 nuclease, SuCas9, was identified from Streptococcus uberis.
- SuCas9 exhibits efficient DNA cleavage activity in vitro.
- SuCas9 functions effectively in human cells and recognizes a novel 5'-NNAAA-3' PAM sequence.
Conclusions:
- SuCas9 represents a valuable addition to the CRISPR-Cas9 toolkit.
- Its compact size and unique PAM specificity offer new opportunities for genome engineering.
- SuCas9 holds potential for future biotechnological and medicinal applications.
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