The new "closed" image of the plague virus NS3 full-length crystal structure (PDB No. 5WX1) has anticytoxase activity.

At present, the genome length of RNA viruses is not more than 35kb, and the coding capacity is very limited.
Therefore, proteins containing more than one functional domain are more common in this type of virus, and the yellow virus NS3 protein, which is the natural fusion of serine protease and super-family two-solutionase, plays a key role in the two important processes of viral polyproteinase solution and genome replication, and the synergy mechanism between the two functional domains is not clear.
The Research Group of Wuhan Virus Research Institute of the Chinese Academy of Sciences has long been engaged in the catalysis and regulation mechanism of polymerase-based RNA virus replication key enzymes, and since October 2013, he has established a cooperative relationship with the Panz Book Group of Wuhan University to jointly study the function mechanism of NS5B polymerase and NS3 protease-de-synthase, which represents the strain of swine fever virus( CSFV).
2015 and 2017, the swine fever virus NS3 derotorase and the full-length crystal structure were reported, but no key in-molecular interactions between proteases and derotorase formation were found in the structure.
Recently, the team parsed a new "closed" image of the NS3 full-length crystal structure (PDB No. 5WX1), in which proteases and decontamination enzymes form an in-molecular interface consisting of three interacting clusters with an area of 2,200 square es, and for the first time discovered that plague virus NS3 can take an image associated with protease shun cutting (the top image in the diagram) is not compatible with reverse cutting (the image below). The
team carried out in-body enzymatic validation of the biological correlation of this closed-type structure and found that the structure had optimal anti-cyclase activity, which could lead to a significant reduction in the activity of the decyclase through point mutation disturbance.
Further tests at the full-length virus level found that the disturbance of the three interactive clusters can affect the formation and size of virus titer and virus phage to varying degrees, and verified the importance of closed-form image to virus replication revealed by crystal structure.
: Swine plague virus NS3 protease-de-throase synergetic pattern diagram.
the closed structure above the
is revealed by the crystal structure analyzed in this study, and the state of the analog protease (Pro) after the smooth cutting of the NS3-NS4A connection point has optimal anti-cylindromatic enzyme (Hel) activity.
the image needs to be converted to an open image (below) before trans-cutting can be achieved, but the activity of the detrost enzyme is reduced.
Yellow virus NS3 not only has its own functional diversity, but also directly participates in regulating the function of viral polymerase, the results of the study not only provide an important basis for the comprehensive interpretation of the function of NS3, but also for further study of NS3 and NS5B polymerase intermodal regulatory mechanism laid a foundation.
this cooperative research is supported by the Ministry of Science and Technology's 973 project "Structural Function Study of Important Viral Transcriptional Replicate Protein Complex" and several projects on the surface of the National Natural Science Foundation of China.
Fengwei, a doctoral student in the Panz Book Group, and Yan Guoliang, an assistant researcher in the Peng Group, are the first authors of the paper.
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