Structural Insights into the Nucleotide-Binding Domains of the P1B-type ATPases HMA6 and HMA8 from Arabidopsis thaliana.
Copper is a crucial ion in cells, but needs to be closely controlled due to its toxic potential and ability to catalyse the formation of radicals. In chloroplasts, an important step for the proper functioning of the photosynthetic electron transfer chain is the delivery of copper to plastocyanin in the thylakoid lumen. The main route for copper transport to the thylakoid lumen is driven by two PIB-type ATPases, Heavy Metal ATPase 6 (HMA6) and HMA8, located in the inner membrane of the chloroplast envelope and in the thylakoid membrane, respectively. Here, the crystal structures of the nucleotide binding domain of HMA6 and HMA8 from Arabidopsis thaliana are reported at 1.5Å and 1.75Å resolution, respectively, providing the first structural information on plants Cu+-ATPases. The structures reveal a compact domain, with two short helices on both sides of a twisted beta-sheet. A double mutant, aiding in the crystallization, provides a new crystal contact, but also avoids an internal clash highlighting the benefits of construct modifications. Finally, the histidine in the HP motif of the isolated domains, unable to bind ATP, shows a side chain conformation distinct from nucleotide bound structures.
Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, Grenoble, France.
Hubert
H
Mayerhofer
Laboratoire de Physiologie Cellulaire et Végétale (LPCV), Institut de Biosciences et Biotechnologies de Grenoble (BIG), Université Grenoble Alpes, CEA, CNRS, INRA, Grenoble, France.
Emeline
E
Sautron
Laboratoire de Physiologie Cellulaire et Végétale (LPCV), Institut de Biosciences et Biotechnologies de Grenoble (BIG), Université Grenoble Alpes, CEA, CNRS, INRA, Grenoble, France.
Norbert
N
Rolland
Laboratoire de Chimie et Biologie des Métaux (LCBM), BIG, Université Grenoble Alpes, CEA, CNRS, INRA, Grenoble, France.
Patrice
P
Catty
Laboratoire de Physiologie Cellulaire et Végétale (LPCV), Institut de Biosciences et Biotechnologies de Grenoble (BIG), Université Grenoble Alpes, CEA, CNRS, INRA, Grenoble, France.
Daphné
D
Seigneurin-Berny
Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, Grenoble, France.
Eva
E
Pebay-Peyroula
Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, Grenoble, France.
Stéphanie
S
Ravaud
D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000737:chemistry* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D003300:Copper / Q000378:metabolism; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D009711:Nucleotides / Q000378:metabolism*; D011485:Protein Binding; D000072417:Protein Domains; D016415:Sequence Alignment
D029681:Arabidopsis Proteins; C000611728:HMA8 protein, Arabidopsis; D009711:Nucleotides; D003300:Copper; D000251:Adenosine Triphosphatases; C000611727:HMA6 protein, Arabidopsis