Crystal structure of the CTP-liganded (T-State) aspartate transcarbamoylase from the extremely thermophilic archaeon Sulfolobus acidocaldariusCrystal structure of the CTP-liganded (T-State) aspartate transcarbamoylase from the extremely thermophilic archaeon Sulfolobus acidocaldarius

Structural highlights

2be9 is a 2 chain structure with sequence from Sulfolobus acidocaldarius. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.6Å
Ligands:, ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

PYRB_SULAC

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

Aspartate carbamoyltransferase (ATCase) is a paradigm for allosteric regulation of enzyme activity. B-class ATCases display very similar homotropic allosteric behaviour, but differ extensively in their heterotropic patterns. The ATCase from the thermoacidophilic archaeon Sulfolobus acidocaldarius, for example, is strongly activated by its metabolic pathway's end product CTP, in contrast with Escherichia coli ATCase which is inhibited by CTP. To investigate the structural basis of this property, we have solved the crystal structure of the S. acidocaldarius enzyme in complex with CTP. Structure comparison reveals that effector binding does not induce similar large-scale conformational changes as observed for the E. coli ATCase. However, shifts in sedimentation coefficients upon binding of the bi-substrate analogue PALA show the existence of structurally distinct allosteric states. This suggests that the so-called "Nucleotide-Perturbation model" for explaining heterotropic allosteric behaviour, which is based on global conformational strain, is not a general mechanism of B-class ATCases.

Crystal structure of Sulfolobus acidocaldarius aspartate carbamoyltransferase in complex with its allosteric activator CTP.,De Vos D, Xu Y, Aerts T, Van Petegem F, Van Beeumen JJ Biochem Biophys Res Commun. 2008 Jul 18;372(1):40-4. Epub 2008 May 12. PMID:18477471[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. De Vos D, Xu Y, Aerts T, Van Petegem F, Van Beeumen JJ. Crystal structure of Sulfolobus acidocaldarius aspartate carbamoyltransferase in complex with its allosteric activator CTP. Biochem Biophys Res Commun. 2008 Jul 18;372(1):40-4. Epub 2008 May 12. PMID:18477471 doi:10.1016/j.bbrc.2008.04.173

2be9, resolution 2.60Å

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