title: African swine fever virus protease, a new viral member of the SUMO-1-specific protease family.
abstract: African swine fever virus (ASFV) is a complex DNA virus that employs polyprotein processing at Gly-Gly-Xaa sites as a strategy to produce several major core components of the viral particle. The virus gene S273R encodes a 31-kDa protein that contains a "core domain" with the conserved catalytic residues characteristic of SUMO-1-specific proteases and the adenovirus protease. Using a COS cell expression system, it was found that protein pS273R is capable of cleaving the viral polyproteins pp62 and pp220 in a specific way giving rise to the same intermediates and mature products as those produced in ASFV-infected cells. Furthermore, protein pS273R, like adenovirus protease and SUMO-1-specific enzymes, is a cysteine protease, because its activity is abolished by mutation of the predicted catalytic histidine and cysteine residues and is inhibited by sulfhydryl-blocking reagents. Protein pS273R is expressed late after infection and is localized in the cytoplasmic viral factories, where it is found associated with virus precursors and mature virions. In the virions, the protein is present in the core shell, a domain where the products of the viral polyproteins are also located. The identification of the ASFV protease will allow a better understanding of the role of polyprotein processing in virus assembly and may contribute to our knowledge of the emerging family of SUMO-1-specific proteases.
authors.affiliation: Centro de Biologia Molecular Severo Ochoa (Consejo Superior de Investigaciones Cientificas-Universidad Autónoma de Madrid), Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Andrés
authors.forename: A
authors.initials: A
authors.lastname: Alejo
authors.forename: C
authors.initials: C
authors.lastname: Simón-Mateo
authors.forename: M L
authors.initials: ML
authors.lastname: Salas
mesh_terms: D000358:African Swine Fever Virus / Q000201:enzymology*; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D002522:Chlorocebus aethiops; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020689:Exopeptidases / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D015971:Gene Expression Regulation, Enzymologic; D015967:Gene Expression Regulation, Viral; D006639:Histidine / Q000235:genetics / Q000378:metabolism; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016296:Mutagenesis; D020815:Polyproteins / Q000737:chemistry / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D016415:Sequence Alignment; D013379:Substrate Specificity; D014162:Transfection; D014709:Vero Cells; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D020815:Polyproteins; D014764:Viral Proteins; D006639:Histidine; D020689:Exopeptidases; C400521:SUMO-1 C-terminal hydrolase; D003546:Cysteine Endopeptidases