Complex formation between recombinant ATP sulfurylase and APS reductase of Allium cepa (L.).
Recombinant ATP sulfurylase (AcATPS1) and adenosine-5'-phosphosulfate reductase (AcAPR1) from Allium cepa have been used to determine if these enzymes form protein-protein complexes in vitro. Using a solid phase binding assay, AcAPR1 was shown to interact with AcATPS1. The AcAPR1 enzyme was also expressed in E. coli as the N-terminal reductase domain (AcAPR1-N) and the C-terminal glutaredoxin domain (AcAPR1-C), but neither of these truncated proteins interacted with AcATPS1. The solid-phase interactions were confirmed by immune-precipitation, where anti-AcATPS1 IgG precipitated the full-length AcAPR1 protein, but not AcAPR1-N and AcAPR1-C. Finally, using the ligand binding assay, full-length AcATPS1 has been shown to bind to membrane-localised full-length AcAPR1. The significance of an interaction between chloroplastidic ATPS and APR in A. cepa is evaluated with respect to the control of the reductive assimilation of sulfate.
Cumming
Mathew
M
Institute of Molecular Biosciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand.
Leung
Susanna
S
McCallum
John
J
McManus
Michael T
MT
D000595:Amino Acid Sequence; D004926:Escherichia coli; D007118:Immunoassay; D047468:Immunoprecipitation; D008024:Ligands; D008969:Molecular Sequence Data; D019697:Onions / Q000201:enzymology*; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism*; D013379:Substrate Specificity; D013430:Sulfate Adenylyltransferase / Q000737:chemistry / Q000378:metabolism*
D008024:Ligands; D011994:Recombinant Proteins; D050862:Oxidoreductases Acting on Sulfur Group Donors; C019618:adenylylsulfate reductase; D013430:Sulfate Adenylyltransferase