PBG Synthase

PDB file 1OHL

This file depicts the yeast Porphobilinogen Synthase, crystallized with the substrate d-aminolevulinic acid (ALA), and having a reaction intermediate resembling porphobilinogen (PBG) linked to a lysine residue at the active site. This structure was solved by P.T. Erskine, L. Coates, D. Butler, J.  H. Youell, A. A. Brindley, S. P. Wood, M. J. Warren, P. M. Shoolingin-Jordan & J. B. Cooper in 2003.

Suggested display options:

Display the protein as cartoon and color structure.
What secondary structure motif is exhibited by this enzyme?
Which glycolysis enzyme shares this structure motif?
Is the active site in the same position in both enzymes?

Select hetero-ligand, display as ball & stick with color CPK, to visualize the reaction intermediate resembling PBG.

Select lys210, lys263. Display as ball & stick with color CPK. Each of these lysine residues initially forms a Schiff base linkages to one of the two ALA substrates.
Identify atoms involved in the Schiff base linkage between the PBG intermediate and one of the active site lysine residues.
Identify the Zinc ion that is postulated to bind a hydroxyl ion that functions as a base during catalysis.

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