Structural studies of E73 from a hyperthermophilic archaeal virus identify the "RH3" domain, an elaborated ribbon-helix-helix motif involved in DNA recognition.

ABSTRACT: Hyperthermophilic archaeal viruses, including Sulfolobus spindle-shaped viruses (SSVs) such as SSV-1 and SSV-Ragged Hills, exhibit remarkable morphology and genetic diversity. However, they remain poorly understood, in part because their genomes exhibit limited or unrecognizable sequence similarity to genes with known function. Here we report structural and functional studies of E73, a 73-residue homodimeric protein encoded within the SSV-Ragged Hills genome. Despite lacking significant sequence similarity, the nuclear magnetic resonance (NMR) structure reveals clear similarity to ribbon-helix-helix (RHH) domains present in numerous proteins involved in transcriptional regulation. In vitro double-stranded DNA (dsDNA) binding experiments confirm the ability of E73 to bind dsDNA in a nonspec

SUBMITTER: Schlenker C 

PROVIDER: S-EPMC3326356 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature