Crystal Structure of a 9-Subunit Archaeal Exosome in Pre-Catalytic States of the Phosphorolytic Reaction
Figure 3
Detailed view of the S. solfataricus exosome active site in complex with RNA and inorganic phosphate. (a) RNA, Pi and contacting residues are shown as sticks (blue for Rrp41 residues and green for Rrp42 residues). An unbiased Fo-Fc electron density map at 3 sigma is displayed in magenta. Two orientations related by a 180 degree rotation around the vertical axis are shown. (b) Position of RNA substrates in the active sites of exosomes from S. solfataricus (RNA displayed in cyan, Rrp41 in blue and Rrp42 in green) and P. abyssi (RNA in magenta, Rrp41 in yellow and Rrp42 in orange) after superimposing the backbone C-alpha atoms. The position of the inorganic phosphate as observed in the S. solfataricus exosome is shown in red. The position of the RNA is very similar in the two different archaeal exosomes.
