title: Viral Evolved Inhibition Mechanism of the RNA Dependent Protein Kinase PKR's Kinase Domain, a Structural Perspective.
abstract: The protein kinase PKR activated by viral dsRNA, phosphorylates the eIF2α, which inhibit the mechanism of translation initiation. Viral evolved proteins mimicking the eIF2α block its phosphorylation and help in the viral replication. To decipher the molecular basis for the PKR's substrate and inhibitor interaction mechanisms, we carried the molecular dynamics studies on the catalytic domain of PKR in complex with substrate eIF2α, and inhibitors TAT and K3L. The studies conducted show the altered domain movements of N lobe, which confers open and close state to the substrate-binding cavity. In addition, PKR exhibits variations in the secondary structural transition of the activation loop residues, and inter molecular contacts with the substrate and the inhibitors. Phosphorylation of the P+1 loop at the Thr-451 increases the affinity of the binding proteins exhibiting its role in the phosphorylation events. The implications of structural mechanisms uncovered will help to understand the basis of the evolution of the host-viral and the viral replication mechanisms.
authors.affiliation: Centre for Bioinformatics, Pondicherry University, Kalapet, Pondicherry, India.
authors.forename: K Hari
authors.initials: KH
authors.lastname: Krishna
authors.affiliation: Centre for Bioinformatics, Pondicherry University, Kalapet, Pondicherry, India.
authors.forename: Yallamandayya
authors.initials: Y
authors.lastname: Vadlamudi
authors.affiliation: Centre for Bioinformatics, Pondicherry University, Kalapet, Pondicherry, India.
authors.forename: Muthuvel Suresh
authors.initials: MS
authors.lastname: Kumar
mesh_terms: D001665:Binding Sites; D015852:Eukaryotic Initiation Factor-2 / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D010766:Phosphorylation; D011485:Protein Binding; D011487:Protein Conformation; D014764:Viral Proteins / Q000737:chemistry* / Q000378:metabolism; D014779:Virus Replication; D019892:eIF-2 Kinase / Q000737:chemistry* / Q000378:metabolism; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000737:chemistry / Q000378:metabolism*
chemical_list: D015852:Eukaryotic Initiation Factor-2; D014764:Viral Proteins; D054322:tat Gene Products, Human Immunodeficiency Virus; D019892:eIF-2 Kinase