1zun
From Proteopedia
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Crystal Structure of a GTP-Regulated ATP Sulfurylase Heterodimer from Pseudomonas syringae
Overview
Sulfate assimilation is a critical component of both primary and secondary metabolism. An essential step in this pathway is the activation of sulfate through adenylation by the enzyme ATP sulfurylase (ATPS), forming adenosine 5'-phosphosulfate (APS). Proteobacterial ATPS overcomes this energetically unfavorable reaction by associating with a regulatory G protein, coupling the energy of GTP hydrolysis to APS formation. To discover the molecular basis of this unusual role for a G protein, we biochemically characterized and solved the X-ray crystal structure of a complex between Pseudomonas syringae ATPS (CysD) and its associated regulatory G protein (CysN). The structure of CysN*D shows the two proteins in tight association; however, the nucleotides bound to each subunit are spatially segregated. We provide evidence that conserved switch motifs in the G domain of CysN allosterically mediate interactions between the nucleotide binding sites. This structure suggests a molecular mechanism by which conserved G domain architecture is used to energetically link GTP turnover to the production of an essential metabolite.
About this Structure
1ZUN is a Protein complex structure of sequences from Pseudomonas syringae and Pseudomonas syringae pv. tomato str. dc3000 with , , and as ligands. Active as Sulfate adenylyltransferase, with EC number 2.7.7.4 Full crystallographic information is available from OCA.
Reference
Molecular basis for G protein control of the prokaryotic ATP sulfurylase., Mougous JD, Lee DH, Hubbard SC, Schelle MW, Vocadlo DJ, Berger JM, Bertozzi CR, Mol Cell. 2006 Jan 6;21(1):109-22. PMID:16387658
Page seeded by OCA on Thu Feb 21 16:19:13 2008
Categories: Protein complex | Pseudomonas syringae | Pseudomonas syringae pv. tomato str. dc3000 | Sulfate adenylyltransferase | Berger, J M. | Bertozzi, C R. | Hubbard, S C. | Lee, D H. | Mougous, J D. | Schelle, M W. | Vocadlo, D J. | AGS | GDP | MG | NA | Beta barrel | G protein | Gtpase | Heterodimer | Pyrophosphate | Switch domain