1R0C

Products in the T State of Aspartate Transcarbamylase: Crystal Structure of the Phosphate and N-carbamyl-L-aspartate Ligated Enzyme

Summary for 1R0C

• Entry DOI: 10.2210/pdb1r0c/pdb
• Related: 1R0B
• Descriptor: Aspartate carbamoyltransferase catalytic chain, Aspartate carbamoyltransferase regulatory chain, PHOSPHATE ION, ... (6 entities in total)
• Functional Keywords: aspartate transcarbamylase, aspartate carbamoyltransferase, products, n-carbamyl-l-aspartate(cla), phosphate, atcase-products complex, t state, transferase
• Biological source: Escherichia coli; More
• Total number of polymer chains: 4
• Total formula weight: 103634.47

Authors

Huang, J.,Lipscomb, W.N. (deposition date: 2003-09-19, release date: 2004-06-08, Last modification date: 2023-08-23)

Primary citation

Huang, J.,Lipscomb, W.N.
Products in the T-State of Aspartate Transcarbamylase: Crystal Structure of the Phosphate and N-Carbamyl-l-aspartate Ligated Enzyme
Biochemistry, 43:6422-6426, 2004

PubMed Abstract: The structure of aspartate transcarbamylase of Escherichia coli ligated to products (phosphate and N-carbamyl-l-aspartate) has been determined at 2.37 A resolution (R-factor = 0.23, R(free) = 0.27). Results might indicate a product release mode, rather than close analogues to the transition state like those found in our earlier studies of other ligands (N-phosphonacetyl-L-aspartate, carbamyl phosphate plus malonate, phosphonoacetamide plus malonate, or citrate plus phosphate). Ordered product release, first carbamylaspartate (CLA) and then phosphate, might be facilitated by a 4 A movement of phosphate from the substrate-analogue position to the product (phosphate) binding position, and by a somewhat similar release movement of the other product (CLA) relative to its analogue (citrate). This movement is consistent with earlier studies of binding of either pyrophosphate or phosphate alone [Honzatko, R. B., and Lipscomb, W. N. (1982) J. Mol. Biol. 160, 265-286].

PubMed: 15157076
DOI: 10.1021/bi0302144

Experimental method

X-RAY DIFFRACTION (2.37 Å)