National Center for
3U01: Crystal structure of onconase double mutant C30A/C75A at 1.12 A resolution
Investigating the effects of double mutation C30A/C75A on onconase structure: Studies at atomic resolution
Biopolymers (2014) 101 p.454-460
The structure of onconase C30A/C75A double mutant has been determined at 1.12A resolution. The structure has high structural homology to other onconase structures. The changes being results of mutation are relatively small, distributed asymmetrically around the two mutated positions, and they are observed not only in the mutation region but expanded to entire molecule. Different conformation of Lys31 side chain that influences the hydrogen bonding network around catalytic triad is probably responsible for lower catalytic efficiency of double mutant. The decrease in thermal stability observed for the onconase variant might be explained by a less dense packing as manifested by the increase of the molecular volume and the solvent accessible surface area.