1QOQ

CRYSTAL STRUCTURE OF WILD-TYPE TRYPTOPHAN SYNTHASE COMPLEXED WITH INDOLE GLYCEROL PHOSPHATE

Summary for 1QOQ

• Entry DOI: 10.2210/pdb1qoq/pdb
• Related: 1A50 1A5A 1A5B 1A5S 1BEU 1BKS 1QOP 1TTP 1TTQ 1UBS 2TRS 2TSY 2WSY
• Descriptor: TRYPTOPHAN SYNTHASE ALPHA CHAIN, TRYPTOPHAN SYNTHASE BETA CHAIN, INDOLE-3-GLYCEROL PHOSPHATE, ... (5 entities in total)
• Functional Keywords: lyase, carbon-oxygen lyase, tryptophan biosynthesis, pyridoxal phosphate
• Biological source: SALMONELLA TYPHIMURIUM; More
• Total number of polymer chains: 2
• Total formula weight: 71934.72

Authors

Weyand, M.,Schlichting, I. (deposition date: 1999-11-15, release date: 2000-11-10, Last modification date: 2023-12-13)

Primary citation

Weyand, M.,Schlichting, I.
Crystal Structure of Wild-Type Tryptophan Synthase Complexed with the Natural Substrate Indole-3-Glycerol Phosphate.
Biochemistry, 38:16469-, 1999

PubMed Abstract: We used freeze trapping to stabilize the Michaelis complex of wild-type tryptophan synthase and the alpha-subunit substrate indole-3-glycerol phosphate (IGP) and determined its structure to 1. 8 A resolution. In addition, we determined the 1.4 A resolution structure of the complex with indole-3-propanole phosphate (IPP), a noncleavable IGP analogue. The interaction of the 3'-hydroxyl of IGP with the catalytic alphaGlu49 leads to a twisting of the propane chain and to a repositioning of the indole ring compared to IPP. Concomitantly, the catalytic alphaAsp60 rotates resulting in a translocation of the COMM domain [betaGly102-betaGly189, for definition see Schneider et al. (1998) Biochemistry 37, 5394-5406] in a direction opposite to the one in the IPP complex. This results in loss of the allosteric sodium ion bound at the beta-subunit and an opening of the beta-active site, thereby making the cofactor pyridoxal 5'-phosphate (PLP) accessible to solvent and thus serine binding. These findings form the structural basis for the information transfer from the alpha- to the beta-subunit and may explain the affinity increase of the beta-active site for serine upon IGP binding.

PubMed: 10600108
DOI: 10.1021/BI9920533

Experimental method

X-RAY DIFFRACTION (1.8 Å)