Two more disulfide bridges in the supplied lysozyme structure, Cys64-Cys80 and Cys76-Cys94, lie close enough together to compare directly. Calculate both SG-SG distances. Is the difference between them large or small relative to the typical covalent S-S single-bond length (about 2.0-2.1 angstrom)? What would a much larger difference (say, one bond at 2.0 angstrom and the other at 2.8 angstrom) have suggested instead?

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. Use S0011: the 8 Cys SG sites of 6LYZ chain A, in residue order 6, 30, 64, 76, 80, 94, 115, 127 (rows 1-8 respectively). Row 3 = Cys64 SG; row 5 = Cys80 SG; row 4 = Cys76 SG; row 6 = Cys94 SG. Report both distances in angstrom to three decimals and answer the qualitative questions in words.

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-0004-asset-1.xyz