3fzd
From Proteopedia
Mutation of Asn28 disrupts the enzymatic activity and dimerization of SARS 3CLpro
Structural highlights
Function[R1A_CVHSA] The papain-like proteinase (PL-PRO) is responsible for the cleavages located at the N-terminus of replicase polyprotein. In addition, PL-PRO possesses a deubiquitinating/deISGylating activity and processes both 'Lys-48'- and 'Lys-63'-linked polyubiquitin chains from cellular substrates. Antagonizes innate immune induction of type I interferon by blocking the phosphorylation, dimerization and subsequent nuclear translocation of host IRF-3.[1] [2] [3] The main proteinase 3CL-PRO is responsible for the majority of cleavages as it cleaves the C-terminus of replicase polyprotein at 11 sites. Recognizes substrates containing the core sequence [ILMVF]-Q-|-[SGACN]. Inhibited by the substrate-analog Cbz-Val-Asn-Ser-Thr-Leu-Gln-CMK (By similarity). Also contains an ADP-ribose-1-phosphate (ADRP)-binding function.[4] [5] [6] Nsp7-nsp8 hexadecamer may possibly confer processivity to the polymerase, maybe by binding to dsRNA or by producing primers utilized by the latter.[7] [8] [9] Nsp9 is a ssRNA-binding protein.[10] [11] [12] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCoronaviruses are responsible for a significant proportion of annual respiratory and enteric infections in humans and other mammals. The most prominent of these viruses is the severe acute respiratory syndrome coronavirus (SARS-CoV) which causes acute respiratory and gastrointestinal infection in humans. The coronavirus main protease, 3CL(pro), is a key target for broad-spectrum antiviral development because of its critical role in viral maturation and high degree of structural conservation among coronaviruses. Dimerization is an indispensable requirement for the function of SARS 3CL(pro) and is regulated through mechanisms involving both direct and long-range interactions in the enzyme. While many of the binding interactions at the dimerization interface have been extensively studied, those that are important for long-range control are not well-understood. Characterization of these dimerization mechanisms is important for the structure-based design of new treatments targeting coronavirus-based infections. Here we report that Asn28, a residue 11 A from the closest residue in the opposing monomer, is essential for the enzymatic activity and dimerization of SARS 3CL(pro). Mutation of this residue to alanine almost completely inactivates the enzyme and results in a 19.2-fold decrease in the dimerization K(d). The crystallographic structure of the N28A mutant determined at 2.35 A resolution reveals the critical role of Asn28 in maintaining the structural integrity of the active site and in orienting key residues involved in binding at the dimer interface and substrate catalysis. These findings provide deeper insight into complex mechanisms regulating the activity and dimerization of SARS 3CL(pro). Mutation of Asn28 disrupts the dimerization and enzymatic activity of SARS 3CL(pro) .,Barrila J, Gabelli SB, Bacha U, Amzel LM, Freire E Biochemistry. 2010 May 25;49(20):4308-17. PMID:20420403[13] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
| ||||||||||||||||||
Categories: Large Structures | Amzel, L M | Bacha, U | Barrila, J | Freire, E | Gabelli, S | Analytical ultracentrifugation | Cytoplasm | Dimerization | Hydrolase | Membrane | Metal-binding | Protease | Ribosomal frameshifting | Rna-binding | Sar | Sars 3clpro | Sars-cov mpro | Thiol protease | Transmembrane | Zinc | Zinc-finger
