Abstract
IM30, the inner membrane-associated protein of 30 kDa, is conserved in cyanobacteria and chloroplasts. Although its exact physiological function is still mysterious, IM30 is clearly essential for thylakoid membrane biogenesis and/or dynamics. Recently, a cryptic IM30 GTPase activity has been reported, albeit thus far no physiological function has been attributed to this. Yet, it is still possible that GTP binding/hydrolysis affects formation of the prototypical large homo-oligomeric IM30 ring and rod structures. Here, we show that the Synechocystis sp. PCC 6803 IM30 protein in fact is an NTPase that hydrolyzes GTP and ATP, but not CTP or UTP, with about identical rates. While IM30 forms large oligomeric ring complexes, nucleotide binding and/or hydrolysis are clearly not required for ring formation.
Keywords:
IM30; PspA; Synechocystis; Vipp1; cyanobacteria; thylakoid membrane.
© 2021 The Authors. FEBS Letters published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenosine Triphosphate / chemistry
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Adenosine Triphosphate / metabolism*
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Bacterial Proteins / genetics
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Bacterial Proteins / metabolism*
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Cloning, Molecular
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Enzyme Assays
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Escherichia coli / genetics
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Escherichia coli / metabolism
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Gene Expression
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Genetic Vectors / chemistry
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Genetic Vectors / metabolism
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Guanosine Triphosphate / chemistry
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Guanosine Triphosphate / metabolism*
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Hydrolysis
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Kinetics
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Membrane Proteins / genetics
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Membrane Proteins / metabolism*
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Microscopy, Electron
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Nucleoside-Triphosphatase / genetics
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Nucleoside-Triphosphatase / metabolism*
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Protein Binding
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Recombinant Proteins / chemistry
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Recombinant Proteins / genetics
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Recombinant Proteins / metabolism
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Substrate Specificity
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Synechocystis / enzymology*
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Synechocystis / genetics
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Synechocystis / ultrastructure
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Thylakoids / enzymology*
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Thylakoids / genetics
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Thylakoids / ultrastructure
Substances
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Bacterial Proteins
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Membrane Proteins
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Recombinant Proteins
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VIPP1 protein, Synechocystis
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Guanosine Triphosphate
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Adenosine Triphosphate
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Nucleoside-Triphosphatase