Crystal Structure of Porcine Reproductive and Respiratory Syndrome Virus Leader Protease Nsp1{alpha}

doi:10.1128/JVI.02579-08

This Article

	Full Text
	Full Text (PDF)
	Alert me when this article is cited
	Alert me if a correction is posted

Services

	Similar articles in this journal
	Similar articles in PubMed
	Alert me to new issues of the journal
	Download to citation manager
	Reprints and Permissions
	Copyright Information
	Books from ASM Press
	MicrobeWorld

Google Scholar

	Articles by Sun, Y.
	Articles by Rao, Z.

PubMed

	PubMed Citation
	Articles by Sun, Y.
	Articles by Rao, Z.

Previous Article | Next Article

Journal of Virology, November 2009, p. 10931-10940, Vol. 83, No. 21
0022-538X/09/$08.00+0 doi:10.1128/JVI.02579-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Crystal Structure of Porcine Reproductive and Respiratory Syndrome Virus Leader Protease Nsp1 ${alpha}$

Yuna Sun,¹^, Fei Xue,²^, Yu Guo,³ Ming Ma,¹ Ning Hao,¹ Xuejun C. Zhang,¹ Zhiyong Lou,²^* Xuemei Li,¹^* and Zihe Rao¹^,2^,3

National Laboratory of Macromolecules, Institute of Biophysics, Chinese Academy of Science, Beijing 100101, China,¹ Structural Biology Laboratory, Tsinghua University, Beijing 100084, China,² College of Life Sciences and Tianjin State Laboratory of Protein Science, Nankai University, Tianjin 300071, China³

Received 15 December 2008/ Accepted 4 August 2009

Porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV),a positive-strand RNA virus that belongs to the Arteriviridaefamily of Nidovirales, has been identified as the causativeagent of PRRS. Nsp1 ${alpha}$ is the amino (N)-terminal protein in a polyproteinencoded by the PRRSV genome and is reported to be crucial forsubgenomic mRNA synthesis, presumably by serving as a transcriptionfactor. Before functioning in transcription, nsp1 ${alpha}$ proteolyticallyreleases itself from nsp1β. However, the structural basisfor the self-releasing and biological functions of nsp1 ${alpha}$ remainselusive. Here we report the crystal structure of nsp1 ${alpha}$ of PRRSV(strain XH-GD) in its naturally self-processed form. Nsp1 ${alpha}$ containsa ZF domain (which may be required for its biological function),a papain-like cysteine protease (PCP) domain with a zinc ionunexpectedly bound at the active site (which is essential forproteolytic self-release of nsp1 ${alpha}$ ), and a carboxyl-terminal extension(which occupies the substrate binding site of the PCP domain).Furthermore, we determined the exact location of the nsp1 ${alpha}$ self-processingsite at Cys-Ala-Met180 ${downarrow}$ Ala-Asp-Val by use of crystallographicdata and N-terminal amino acid sequencing. The crystal structurealso suggested an in cis self-processing mechanism for nsp1 ${alpha}$ .Furthermore, nsp1 ${alpha}$ appears to have a dimeric architecture bothin solution and as a crystal, with a hydrophilic groove on themolecular surface that may be related to nsp1 ${alpha}$ 's biological function.Compared with existing structure and function data, our resultssuggest that PRRSV nsp1 ${alpha}$ functions differently from other reportedviral leader proteases, such as that of foot-and-mouth disease.

* Corresponding author. Mailing address for Zhiyong Lou: Laboratory of Structural Biology, New Lifescience Building, Tsinghua University, Beijing 100084, China. Phone: 86-10-62771493. Fax: 86-10-62773145. E-mail: louzy{at}xtal.tsinghua.edu.cn. Mailing address for Xuemei Li: National Laboratory of Macromolecules, Institute of Biophysics, Chinese Academy of Science, Beijing 100101, China. Phone: 86-10-64888556. Fax: 86-10-64871293. E-mail: lixm{at}sun5.ibp.ac.cn

Published ahead of print on 12 August 2009.

These authors contribute equally to this work.