2air | pdb_00002air

T-state Active Site of Aspartate Transcarbamylase:Crystal Structure of the Carbamyl Phosphate and L-alanosine Ligated Enzyme

spinqualitylabelsall models 2air, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2air is a 4 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: AL0, CP, ZN Gene: pyrB (Escherichia coli), pyrI (Escherichia coli) Activity: Aspartate carbamoyltransferase, with EC number 2.1.3.2 Resources: FirstGlance, OCA, RCSB, PDBsum 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 An X-ray diffraction study to 2.0 A resolution shows that this enzyme, ATCase, is in the T-state (the c3 to c3 distance is 45.2 A) when ATCase is bound to carbamyl phosphate (CP) and to L-alanosine (an analogue of aspartate). This result strongly supports the kinetic results that alanosine did not inhibit the carbamylation of aspartate in the normal reaction of native ATCase plus CP and aspartate [Baillon, J., Tauc, P., and Herve, G. (1985) Biochemistry 24, 7182-7187]. The structure further reveals that the phosphate of CP is 4 A away from its known position in the R-state and is in the T-state position of P(i) in a recent study of ATCase complexed with products, phosphate (P(i)) and N-carbamyl-L-aspartate [Huang, J., and Lipscomb, W. N. (2004) Biochemistry 43, 6422-6426]. Moreover, the alanosine position in this T-state is somewhat displaced from that expected for its analogue, aspartate, from the R-state position. The relations of these structural aspects to the kinetics are presented. T-state active site of aspartate transcarbamylase: crystal structure of the carbamyl phosphate and L-alanosine ligated enzyme.,Huang J, Lipscomb WN Biochemistry. 2006 Jan 17;45(2):346-52. PMID:16401065 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Aspartate carbamoyltransferase

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