Fig. 1

Properties of QKI6. a SEC-MALS profile of QKI6 displays mainly a dimer. The purity of QKI6 was determined using SDS-PAGE (inset). b Top: The sequence of QKI6. Secondary structure prediction is shown below the sequence. The C-terminal tail (underlined) has not been structurally characterized. Cys and Met residues are highlighted in bold. Bottom: Crystal structure of the QKI6 STAR domain in complex with an RNA oligonucleotide (PDB ID: 4jvh [19]) is presented with the subdomains annotated. Coloring matches the protein sequence. The RNA oligonucleotide (5′-ACUAACAA-3′) is shown as gray sticks. Cys and Met residues are shown as sticks. c Thermal stability experiments of QKI6 reveal that its T_m is increased in elevated pH and moderate salt content. Additionally, phosphate produces another melting event at ~ 71 °C. Each condition was measured twice. All pH values were tested in the absence of NaCl. All salt concentrations were tested in 50 mM BICINE, pH 8.0. The effect of additives was tested in 50 mM BICINE, pH 8.0, 150 mM NaCl