1UCW

COMPLEX OF TRANSALDOLASE WITH THE REDUCED SCHIFF-BASE INTERMEDIATE

Summary for 1UCW

• Entry DOI: 10.2210/pdb1ucw/pdb
• Descriptor: TRANSALDOLASE (2 entities in total)
• Functional Keywords: transferase, ketone residues, pentose shunt
• Biological source: Escherichia coli
• Cellular location: Cytoplasm (Probable): P0A870
• Total number of polymer chains: 2
• Total formula weight: 70720.40

Authors

Jia, J.,Lindqvist, Y.,Schneider, G. (deposition date: 1996-11-14, release date: 1997-07-07, Last modification date: 2024-06-05)

Primary citation

Jia, J.,Schorken, U.,Lindqvist, Y.,Sprenger, G.A.,Schneider, G.
Crystal structure of the reduced Schiff-base intermediate complex of transaldolase B from Escherichia coli: mechanistic implications for class I aldolases.
Protein Sci., 6:119-124, 1997

PubMed Abstract: Transaldolase catalyzes transfer of a dihydroxyacetone moiety from a ketose donor to an aldose acceptor. During catalysis, a Schiff-base intermediate between dihydroxyacetone and the epsilon-amino group of a lysine residue at the active site of the enzyme is formed. This Schiff-base intermediate has been trapped by reduction with potassium borohydride, and the crystal structure of this complex has been determined at 2.2 A resolution. The overall structures of the complex and the native enzyme are very similar; formation of the intermediate induces no large conformational changes. The dihydroxyacetone moiety is covalently linked to the side chain of Lys 132 at the active site of the enzyme. The Cl hydroxyl group of the dihydroxyacetone moiety forms hydrogen bonds to the side chains of residues Asn 154 and Ser 176. The C3 hydroxyl group interacts with the side chain of Asp 17 and Asn 35. Based on the crystal structure of this complex a reaction mechanism for transaldolase is proposed.

PubMed: 9007983

Experimental method

X-RAY DIFFRACTION (2.2 Å)