3mpu | pdb_00003mpu

Crystal structure of the C47A/A241C disulfide-linked E. coli Aspartate Transcarbamoylase holoenzyme

spinqualitylabelsall models 3mpu, resolution 2.85Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3mpu is a 6 chain structure with sequence from Ecoli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: PO4, ZN Related: 1d09, 2a0f, 1at1, 1r0b, 1za2 Gene: b4245, JW4204, pyrB, pyrI (ECOLI), pyrI, b4244, JW4203 (ECOLI) Activity: Aspartate carbamoyltransferase, with EC number 2.1.3.2 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [PYRI_ECOLI] Involved in allosteric regulation of aspartate carbamoyltransferase.[HAMAP-Rule:MF_00002] 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 The pathway of product release from the R state of aspartate transcarbamoylase (ATCase; EC 2.1.3.2, aspartate carbamoyltransferase) has been determined here by solving the crystal structure of Escherichia coli ATCase locked in the R quaternary structure by specific introduction of disulfide bonds. ATCase displays ordered substrate binding and product release, remaining in the R state until substrates are exhausted. The structure reported here represents ATCase in the R state bound to the final product molecule, phosphate. This structure has been difficult to obtain previously because the enzyme relaxes back to the T state after the substrates are exhausted. Hence, cocrystallizing the wild-type enzyme with phosphate results in a T-state structure. In this structure of the enzyme trapped in the R state with specific disulfide bonds, we observe two phosphate molecules per active site. The position of the first phosphate corresponds to the position of the phosphate of carbamoyl phosphate (CP) and the position of the phosphonate of N-phosphonacetyl-l-aspartate. However, the second, more weakly bound phosphate is bound in a positively charged pocket that is more accessible to the surface than the other phosphate. The second phosphate appears to be on the path that phosphate would have to take to exit the active site. Our results suggest that phosphate dissociation and CP binding can occur simultaneously and that the dissociation of phosphate may actually promote the binding of CP for more efficient catalysis. The pathway of product release from the R state of aspartate transcarbamoylase.,Mendes KR, Kantrowitz ER J Mol Biol. 2010 Sep 3;401(5):940-8. Epub 2010 Jul 8. PMID:20620149 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Aspartate carbamoyltransferase

Proteopedia Page Contributors and Editors (what is this?)

OCA