The supplied lysozyme structure's own SSBOND record pairs Cys6 and Cys127 as a disulfide bridge. Using the supplied SG (sulfur) coordinates, calculate the Cys6-Cys127 SG-SG distance. Report the distance in angstrom to three decimal places. Why must this distance be short enough to represent a real covalent S-S bond rather than two sulfurs that merely happen to be nearby?

Coordinates are in angstrom (1 nm = 10 angstrom). XYZ atom rows are one-based after the two header lines. Use the supplied coordinate snapshot without optimization or periodic wrapping; this is a single deposited crystal model. Use S0011 only: the 8 Cys SG (sulfur) sites of 6LYZ chain A, in residue order 6, 30, 64, 76, 80, 94, 115, 127 (rows 1-8 respectively). Row 1 = Cys6 SG; row 8 = Cys127 SG. Report the distance in angstrom to three decimals.

8
PDB 6LYZ hen egg-white lysozyme, 8 Cys SG (disulfide sulfur) sites in residue order 6,30,64,76,80,94,115,127, chain A, model 1; angstrom
S -9.062 21.202 2.777
S -1.561 29.508 11.989
S 5.622 13.979 26.390
S -1.502 16.173 28.624
S 7.226 12.794 26.597
S -0.751 16.286 26.655
S -0.692 29.682 13.829
S -9.740 22.242 4.384


Attachments:
S0011: item-0001-asset-1.xyz