1GPW

Structural evidence for ammonia tunneling across the (beta/alpha)8 barrel of the imidazole glycerol phosphate synthase bienzyme complex.

Summary for 1GPW

• Entry DOI: 10.2210/pdb1gpw/pdb
• Related: 1THF
• Descriptor: HISF PROTEIN, AMIDOTRANSFERASE HISH, PHOSPHATE ION, ... (4 entities in total)
• Functional Keywords: lyase/transferase, complex (lyase-transferase), histidine biosynthesis, glutaminase, glutamine amidotransferase, cyclase, ammonia channel, lyase-transferase complex
• Biological source: THERMOTOGA MARITIMA; More
• Total number of polymer chains: 6
• Total formula weight: 153220.18

Authors

Walker, M.,Beismann-Driemeyer, S.,Sterner, R.,Wilmanns, M. (deposition date: 2001-11-12, release date: 2002-02-10, Last modification date: 2023-12-13)

Primary citation

Douangamath, A.,Walker, M.,Beismann-Driemeyer, S.,Vega-Fernandez, M.C.,Sterner, R.,Wilmanns, M.
Structural Evidence for Ammonia Tunneling Across the (Beta Alpha)(8) Barrel of the Imidazole Glycerol Phosphate Synthase Bienzyme Complex.
Structure, 10:185-, 2002

PubMed Abstract: Since reactive ammonia is not available under physiological conditions, glutamine is used as a source for the incorporation of nitrogen in a number of metabolic pathway intermediates. The heterodimeric ImGP synthase that links histidine and purine biosynthesis belongs to the family of glutamine amidotransferases in which the glutaminase activity is coupled with a subsequent synthase activity specific for each member of the enzyme family. Its X-ray structure from the hyperthermophile Thermotoga maritima shows that the glutaminase subunit is associated with the N-terminal face of the (beta alpha)(8) barrel cyclase subunit. The complex reveals a putative tunnel for the transfer of ammonia over a distance of 25 A. Although ammonia tunneling has been reported for glutamine amidotransferases, the ImGP synthase has evolved a novel mechanism, which extends the known functional properties of the versatile (beta alpha)(8) barrel fold.

PubMed: 11839304
DOI: 10.1016/S0969-2126(02)00702-5

Experimental method

X-RAY DIFFRACTION (2.4 Å)