title: Recapitulating the Structural Evolution of Redox Regulation in Adenosine 5'-Phosphosulfate Kinase from Cyanobacteria to Plants.
abstract: In plants, adenosine 5'-phosphosulfate (APS) kinase (APSK) is required for reproductive viability and the production of 3'-phosphoadenosine 5'-phosphosulfate (PAPS) as a sulfur donor in specialized metabolism. Previous studies of the APSK from Arabidopsis thaliana (AtAPSK) identified a regulatory disulfide bond formed between the N-terminal domain (NTD) and a cysteine on the core scaffold. This thiol switch is unique to mosses, gymnosperms, and angiosperms. To understand the structural evolution of redox control of APSK, we investigated the redox-insensitive APSK from the cyanobacterium Synechocystis sp. PCC 6803 (SynAPSK). Crystallographic analysis of SynAPSK in complex with either APS and a non-hydrolyzable ATP analog or APS and sulfate revealed the overall structure of the enzyme, which lacks the NTD found in homologs from mosses and plants. A series of engineered SynAPSK variants reconstructed the structural evolution of the plant APSK. Biochemical analyses of SynAPSK, SynAPSK H23C mutant, SynAPSK fused to the AtAPSK NTD, and the fusion protein with the H23C mutation showed that the addition of the NTD and cysteines recapitulated thiol-based regulation. These results reveal the molecular basis for structural changes leading to the evolution of redox control of APSK in the green lineage from cyanobacteria to plants.
authors: From the Department of Biology, Washington University, St. Louis, Missouri 63130.
authors: Jonathan
authors: J
authors: Herrmann
authors: From the Department of Biology, Washington University, St. Louis, Missouri 63130.
authors: David
authors: D
authors: Nathin
authors: From the Department of Biology, Washington University, St. Louis, Missouri 63130.
authors: Soon Goo
authors: SG
authors: Lee
authors: From the Department of Biology, Washington University, St. Louis, Missouri 63130.
authors: Tony
authors: T
authors: Sun
authors: From the Department of Biology, Washington University, St. Louis, Missouri 63130 jjez@biology2.wustl.edu.
authors: Joseph M
authors: JM
authors: Jez
mesh_terms: D000250:Adenosine Phosphosulfate / Q000378:metabolism; D000266:Adenylyl Imidodiphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology; D018360:Crystallography, X-Ray; D000458:Cyanobacteria / Q000201:enzymology*; D019143:Evolution, Molecular; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000737:chemistry* / Q000378:metabolism*; D010944:Plants / Q000201:enzymology*; D017434:Protein Structure, Tertiary; D046939:Synechocystis / Q000201:enzymology
chemical_list: D000266:Adenylyl Imidodiphosphate; D000250:Adenosine Phosphosulfate; D017853:Phosphotransferases (Alcohol Group Acceptor); C019617:adenylylsulfate kinase; D008274:Magnesium
keywords: Arabidopsis; plant biochemistry; protein structure; redox regulation; sulfur