A PKR-like eukaryotic initiation factor 2alpha kinase from zebrafish contains Z-DNA binding domains instead of dsRNA binding domains.

ABSTRACT: The double-stranded RNA (dsRNA)-dependent protein kinase (PKR) is induced as part of the IFN response in mammals and acts to shut down protein synthesis by the phosphorylation of eukaryotic initiation factor 2alpha (eIF2alpha). In fish, a PKR-like kinase activity has been detected, but the enzyme responsible has eluded characterization. Here, we describe a PKR-like kinase from zebrafish. Phylogenetic analysis shows that the C-terminal kinase domain is more closely related to the kinase domain of PKR than to any of the other three known eIF2alpha kinases. Surprisingly, instead of the two dsRNA binding domains found at the N terminus of PKR, there are two Zalpha domains. Zalpha domains specifically bind dsDNA and RNA in the left-handed Z conformation, often with high affinity. They have been

SUBMITTER: Rothenburg S 

PROVIDER: S-EPMC547857 | biostudies-literature | 2005 Feb

REPOSITORIES: biostudies-literature