Figure 2

Models of human ADPRibase-Mn with docked substrates. The coordinates for the models were taken from previous work⁵⁵ and the structures were drawn with VMD 1.9.3 (http://www.ks.uiuc.edu/Research/vmd/)⁷⁷ under MacOSX. (a,b) Full view of ADPRibase-Mn with docked ADP-ribose (a) or cADPR (b) showing in both cases the amino acid residues that were mutated in this work. (c) Stereogram with the detail of cADPR docked to ADPRibase-Mn showing: (i) the ligand (dark blue, adenine; green, ‘southern’ ribose; purple, pyrophosphate; orange, ‘northern’ ribose); (ii) the metals (yellow) of the dinuclear centre with a bridging molecule of water (red) which is assumed to act as nucleophile in the reactions; (iii) amino acid residues bound to the metals (black), of which Gln²⁷ and Asp¹¹⁰ have been mutated in previous work; (iv) other amino acids mutated previously but not in the current work (Arg⁴³, His¹¹¹ and Phe²¹⁰); (v) amino acids mutated in the current work (Phe³⁷, Leu¹⁹⁶, Asp²⁵⁰, Val²⁵², Cys²⁵³ and Thr²⁷⁹).