Abstract
The Get3 ATPase directs the delivery of tail-anchored (TA) proteins to the endoplasmic reticulum (ER). TA-proteins are characterized by having a single transmembrane helix (TM) at their extreme C terminus and include many essential proteins, such as SNAREs, apoptosis factors, and protein translocation components. These proteins cannot follow the SRP-dependent co-translational pathway that typifies most integral membrane proteins; instead, post-translationally, these proteins are recognized and bound by Get3 then delivered to the ER in the ATP dependent Get pathway. To elucidate a molecular mechanism for TA protein binding by Get3 we have determined three crystal structures in apo and ADP forms from Saccharomyces cerevisae (ScGet3-apo) and Aspergillus fumigatus (AfGet3-apo and AfGet3-ADP). Using structural information, we generated mutants to confirm important interfaces and essential residues. These results point to a model of how Get3 couples ATP hydrolysis to the binding and release of TA-proteins.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
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Adenosine Triphosphatases / chemistry*
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Adenosine Triphosphatases / genetics
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Adenosine Triphosphatases / metabolism
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Aspergillus fumigatus / enzymology*
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Crystallography, X-Ray
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Guanine Nucleotide Exchange Factors / chemistry*
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Guanine Nucleotide Exchange Factors / genetics
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Guanine Nucleotide Exchange Factors / metabolism
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Membrane Fusion Proteins / chemistry
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Membrane Fusion Proteins / metabolism*
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Models, Molecular
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Nucleic Acid Conformation
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Nucleotides / chemistry
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Nucleotides / metabolism
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Phenotype
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Protein Binding
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Protein Structure, Quaternary
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Protein Structure, Tertiary
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Saccharomyces cerevisiae / enzymology*
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Saccharomyces cerevisiae Proteins / chemistry*
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Saccharomyces cerevisiae Proteins / genetics
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Saccharomyces cerevisiae Proteins / metabolism
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Structural Homology, Protein
Substances
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Guanine Nucleotide Exchange Factors
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Membrane Fusion Proteins
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Nucleotides
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Saccharomyces cerevisiae Proteins
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Adenosine Triphosphatases
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Get3 protein, S cerevisiae