TtAgo is able to independently generate and selectively load functional DNA guide chains.

On March 2, the journal Molecular Cell published online the latest research by Wang Yanli of the Institute of Biophysics of the Chinese Academy of Sciences and his collaborators on the independent generation and loading of DNA-guided chains by the bacteria Argonaute (Ago) protein, entitled Autoomous Generation and Loading of DNA Guides by Bacterial Argonaute.
proteins of endo-nuclear organisms are important parts of the RNA interference path, using small RNA guide chains to target complementary paired RNA molecules.
of RNA-guided chains is a series of catalytic reactions that are completed by different enzymes.
Ago protein is also present in prokernel organisms, which are involved in the resistance to foreign invasion of DNA.
the use of RNA-guided chains to target RNA molecules, and numerous studies have shown that prokernel Ago proteins use DNA-guided chains to target DNA molecules.
the molecular mechanism of how small interfering DNA (small interfering DNA, siDNA) guide chains are produced and loaded into the prokernel Ago protein remains to be studied.
Tt Ago, which is called Thermusthermophilus, is able to interfere with transformed protons under the guidance of siDNA.
these siDNA guide chains are 5' phosphate, 13-25nt long.
most of the SiDNA combined with TtAgo is deoxygenated at the end of 5', suggesting that the formation and loading of the boot chain has a special mechanism.
the TtAgo Protein Generation and Loading DNA Guide Chain Diagram In this study, Wang Yanli's team and their collaborators found that TtAgo was able to independently generate and selectively load functional DNA guide chains.
study found that TtAgo was able to degrade unstable double-stranded DNA, producing small double-stranded DNA fragments, and TtAgo was able to selectively load the degraded DNA and then guide the degradation of the target DNA.
combined with single-molecule fluorescence, molecular dynamics, and structural studies, the researchers found that TtAgo-loaded double-stranded DNA molecules preferred the passer-by chain at the 5' end of the guide chain to contain deoxygenation.
this explains why TtAgo prioritizes loading a boot chain containing 5' end deoxycytides in the body.
Wang Yanli is the co-author of the paper, senior engineer Sheng Gang is the co-first author of the article, and researchers Yu Jizhong and Dr. Zhang Yong of the Institute of Biophysics have done important work in molecular simulation.
the study was funded by the National Natural Science Foundation of China (project number: 91440201) and the Chinese Academy of Sciences strategic pilot science and technology special (Category B, project number: XDB08010203), shanghai synchred radiation light source for the study provided important technical support.
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