Figure 3.

The active site. (a) Superposition of the catalytic triads of yeast Hsp33 (yellow), yeast Hsp31 (red) and E. coli Hsp31 (green). Only the Hsp33 numbering is indicated. (b) The electron density around Cys-SOH138 in the catalytic triad of yeast Hsp33. 2F _o − F _c electron density contoured at 1.0σ (0.28 e Å⁻³) is shown in blue and F _o − F _c electron density contoured at 3.0σ (0.17 e Å⁻³) is shown in green.