Structural characterization of the Get4/Get5 complex and its interaction with Get3
The recently elucidated Get proteins are responsible for the targeted delivery of the majority of tail-anchored (TA) proteins to the endoplasmic reticulum. Get4 and Get5 have been identified in the early steps of the pathway mediating TA substrate delivery to the cytoplasmic targeting factor Get3. Here we report a crystal structure of Get4 and an N-terminal fragment of Get5 from Saccharomyces cerevisae. We show Get4 and Get5 (Get4/5) form an intimate complex that exists as a dimer (two copies of Get4/5) mediated by the C-terminus of Get5. We further demonstrate that Get3 specifically binds to a conserved surface on Get4 in a nucleotide dependent manner. This work provides further evidence for a model in which Get4/5 operates upstream of Get3 and mediates the specific delivery of a TA substrate.
© 2010 by the National Academy of Sciences. Freely available online through the PNAS open access option. Communicated by Douglas C. Rees, Caltech/HHMI, Pasadena, CA, May 4, 2010 (received for review March 8, 2010). We thank J. Howard, A. Müller, and A. Palazzo for discussion and critical comments on the manuscript, and T. Walton for help with MALS. We thank Gordon and Betty Moore for support of the Molecular Observatory at Caltech. All data collection was performed at beamline 9-2 and 11-1 at SSRL. Operations at Stanford Synchrotron Radiation Laboratory are supported by the US Department of Energy and the National Institutes of Health. W.M.C. is supported by the Searle Scholar program and a Burroughs– Wellcome Fund Career Award for the Biological Sciences. Author contributions: J.W.C. and W.M.C. designed research; J.W.C. performed research; J.W.C., C.J.M.S., and M.Z. contributed new reagents/analytic tools; J.W.C. and W.M.C. analyzed data; and J.W.C., C.J.M.S., and W.M.C. wrote the paper.
Published - Chartron2010p10855P_Natl_Acad_Sci_Usa.pdf
Supplemental Material - pnas.1006036107_SI.pdf