Are All Proteins Enzymes?

Have you considered that are all proteins enzymes? Recently, Prof. Lixin Ma's team at the School of Life Sciences and the State Key Laboratory of Biocatalysis and Enzyme Engineering of Hubei University, where Fei Wang works, reported a pAgo protein from the cold-tolerant bacterium Mucilaginibacter paludis, MbpAgo, which It is also the first pAgo that prefers to cut RNA at room temperature.

　　The team says this work both expands the understanding of Ago proteins and provides new options for developing programmable nuclease tools that target RNA. As a tool enzyme for RNA manipulation, MbpAgo could be used as a new means of developing in vivo or in vitro targeted RNA. Do scientists study proteins that are all proteins enzymes.

According to Fei Wang, the group has previously developed a series of assays based on PfAgo to detect DNA and RNA. Their discovery of MbpAgo, which can be used as a programmable nuclease for targeting RNA, has the potential to develop a technology based on the specific detection of RNA by MbpAgo.

　　Currently, it has been reported that PfAgo and TtAgo can be used to target wild-type nucleic acid molecules to enrich for mutants, enabling highly sensitive detection of mutants. The team can also use MbpAgo to enrich for RNA mutants by efficiently cleaving RNA activity, and to process RNA ends to produce end-uniform RNA products. Some experiments argue that are all proteins enzymes.

　　Cas13, which is capable of targeting RNA, has been described as being used for RNA virus removal in vivo. Therefore, MbpAgo can also be attempted for in vivo RNA virus clearance. In addition, MbpAgo can be fused with various enzymes involved in cascade catalysis to take advantage of the RNA scaffolding effect and improve the efficiency of the catalytic reaction.

This research starts with the CRISPR-Cas system, a Cas effector protein that serves as a programmable nuclease tool and enables efficient editing of the genomes of a wide range of cells and organisms. Currently, the CRISPR-Cas system has shown great potential for applications in multiple fields such as genetic engineering and biomedicine.

　　Cas proteins require targeted cleavage of complementary target DNA or target RNA mediated by a specific guide RNA, which is typically around 100nt (Cas9) or 43nt (Cas12) in length and requires recognition of a specific PAM motif when cleaving DNA. So, are all proteins enzymes?

　　As another class of programmable nuclease tools, pAgos proteins use DNA or RNA of 15-25nt in length as a guide to target DNA or RNA for cleavage. pAgos is more widely distributed and functionally diverse in prokaryotes than Cas proteins.

　　To date, only a few pAgos have been investigated for their structural or biochemical properties. pAgos are not known to be the next generation of gene editing tools. Therefore, it is important to explore new pAgos proteins, especially pAgos with high catalytic activity at moderate temperatures, for the development of new programmable nuclease tools.

The group has been engaged in the research of gene editing tools development and application, especially the biochemical properties and catalytic mechanism of pAgos. The pAgos with catalytic activity have been reported from thermophilic and mesophilic microorganisms. The biochemical properties and catalytic mechanisms of pAgos from cold-tolerant or cold-loving microbial sources have not been previously investigated.

　　In this work, Fei Wang and colleagues systematically investigated the biochemical properties of MbpAgo derived from the cold-tolerant bacterium Mucilaginibacter paludis. They found that MbpAgo prefers to cleave RNA, a property that is very different from the studied pAgos but similar to eAgos. Most of the currently reported pAgos favor DNA targets, while eukaryotic Ago proteins (eAgos) favor RNA targets.

　　In addition, the team found that MbpAgo can have efficient cleavage activity at 37°C, despite the fact that the growth temperature of the cold-tolerant bacterium Bacillus marsupialis is 2-33°C, with an optimal growth temperature of 20°C.Have you considered that are all proteins enzymes?