Lysozyme

130 residues that cut the sugar backbone of a bacterial cell wall, and the first enzyme anyone watched work. One camera, .

the enzyme

what you are looking at

modelled
completeness
helix / strand
segments
disulfides
catalytic pair
in the cleft
vs the reference
same-protein baseline
where it moves
extents Å
view

The baseline row is a structure this page does not draw: another crystal of the empty protein, by another group, fitted the same way. It is what says whether the row above it is a large number. Colour is secondary structure, the repo default. The ball-and-stick is the catalytic pair, and the sugar where a view has one. Every figure above is counted off the deposition by the baker.

Not drawn: the disease. Point substitutions in this protein cause hereditary systemic amyloidosis, in which lysozyme deposits as fibrils in the liver, kidney and spleen over decades. It is rare, and it is not something a crystal shows: the variants fold correctly and what the mutation costs is stability, so the aggregating form is a partly unfolded state no deposition contains. Two variant structures were baked during review and dropped — I56T is 0.23 Å from wild type, inside the noise, while D67H throws two loops 9.7 Å out, and both cause the same illness the same way. Drawn side by side they would say the visible one is the worse one, which is false.

Turn the molecule, then copy. Paste into view.basis in proteins.js with by: 'human', then reload. No re-bake: a chosen basis is read at draw time.

RCSB entry deposited .pdb what this page loads