Structural basis of GDP release and gating in G protein coupled Fe2+ transport

• Published in: The EMBO journal Vol. 28; no. 17; pp. 2677 - 2685
• Main Authors: Guilfoyle, Amy, Maher, Megan J, Rapp, Mikaela, Clarke, Ronald, Harrop, Stephen, Jormakka, Mika
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 02.09.2009; Nature Publishing Group UK; Springer Nature B.V; Nature Publishing Group
• Subjects: Binding Sites; Biological Transport; Cation Transport Proteins - chemistry; Cation Transport Proteins - metabolism; crystallography; Cytoplasm - metabolism; EMBO37; EMBO40; Escherichia coli Proteins - chemistry; Escherichia coli Proteins - metabolism; GDP release; GTP-Binding Proteins - chemistry; GTP-Binding Proteins - metabolism; GTPase; Guanosine Diphosphate - chemistry; Guanosine Diphosphate - metabolism; Iron - metabolism; iron transport; Membrane processes; Membranes; Models, Molecular; Molecular biology; Molecular structure; Protein Conformation; Proteins; Signal Transduction; crystallography; GDP release; iron transport; GTPase
• ISSN: 0261-4189; 1460-2075; 1460-2075
• DOI: 10.1038/emboj.2009.208

G proteins are key molecular switches in the regulation of membrane protein function and signal transduction. The prokaryotic membrane protein FeoB is involved in G protein coupled Fe 2+ transport, and is unique in that the G protein is directly tethered to the membrane domain. Here, we report the structure of the soluble domain of FeoB, including the G protein domain, and its assembly into an unexpected trimer. Comparisons between nucleotide free and liganded structures reveal the closed and open state of a central cytoplasmic pore, respectively. In addition, these data provide the first observation of a conformational switch in the nucleotide‐binding G5 motif, defining the structural basis for GDP release. From these results, structural parallels are drawn to eukaryotic G protein coupled membrane processes.