Expression, purification and structural analysis of the Pyrococcus abyssi RNA binding protein PAB1135

BACKGROUND: The gene coding for the uncharacterized protein PAB1135 in the archaeon Pyrococcus abyssi is in the same operon as the ribonuclease P (RNase P) subunit Rpp30. FINDINGS: Here we report the expression, purification and structural analysis of PAB1135. We analyzed the interaction of PAB1135 with RNA and show that it binds efficiently double-stranded RNAs in a non-sequence specific manner. We also performed molecular modeling of the PAB1135 structure using the crystal structure of the protein Af2318 from Archaeoglobus fulgidus (2OGK) as the template. CONCLUSIONS: Comparison of this model has lead to the identification of a region in PAB1135 that could be involved in recognizing double-stranded RNA.