1q95

Aspartate Transcarbamylase (ATCase) of Escherichia coli: A New Crystalline R State Bound to PALA, or to Product Analogues Phosphate and Citrate

spinqualitylabelsall models 1q95, resolution 2.46Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1q95 is a 12 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.46Å Ligands: PAL, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function PYRB_ECOLI Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Structures of the R-state of Escherichia coli ATCase maintained with carbamyl phosphate and succinate, phosphonoacetamide and malonate, or N-phosphonacetyl-l-aspartate (PALA) have previously been made in the space group P321, in which the two independent r (regulatory) and two independent c (catalytic) chains are repeated by crystallographic symmetry to yield the holoenzyme c(6)r(6), ((c(3))(2)(r(2))(3)). The exploration of a new crystalline R-state P2(1)2(1)2(1) was undertaken to examine the c(3).c(3) expansion of 11 A in the T-to-R transition, and to further test whether intermolecular contacts influence the binding of PALA. The results show that the expansion along the 3-fold axis is 10 A, and that the binding modes of the six crystallographic independent PALA molecules are virtually identical to one another, and to modes described previously. As further test, the PALA, a bisubstrate analogue, was displaced by citrate and phosphate, where citrate is an analogue of product carbamylaspartate. The results support the conclusions about the binding of the three previously studied analogues, and further support, within about 0.5 A, the structure proposed for the transition state [Gouaux, J. E., Krause, K. L., and Lipscomb, W. N. (1987) Biochem. Biophys. Res. Commun. 142, 893-897; Jin, L., Stec, B., Lipscomb, W. N., and Kantrowitz, E. R. (1999) Proteins: Struct., Funct., Genet. 37, 729-742]. Aspartate transcarbamylase (ATCase) of Escherichia coli: a new crystalline R-state bound to PALA, or to product analogues citrate and phosphate.,Huang J, Lipscomb WN Biochemistry. 2004 Jun 1;43(21):6415-21. PMID:15157075 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Aspartate carbamoyltransferase 3D structures

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