Abstract
Site-directed mutagenesis was used to change four amino acid residues (Q82, P152, L179, H192) in the MalK subunit of S. typhimurium maltose transport system which are highly conserved among members of the ATP-binding cassette (ABC) family. Replacement of H192 caused complete failure to complement the transport defect of a malK strain whereas changes of the other residues resulted in reduced or wild-type activity. The purified mutant proteins exhibited ATPase activity comparable to wild-type MalK.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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ATP-Binding Cassette Transporters*
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Adenosine Triphosphate / metabolism*
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Bacterial Proteins / genetics*
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Carrier Proteins / genetics*
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Electrophoresis, Polyacrylamide Gel
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Membrane Proteins / genetics*
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Mutagenesis, Site-Directed*
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Plasmids
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Protein Conformation
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Salmonella typhimurium / metabolism
Substances
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ATP-Binding Cassette Transporters
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Bacterial Proteins
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Carrier Proteins
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MalK protein, Bacteria
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MalK protein, Salmonella typhimurium
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Membrane Proteins
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Adenosine Triphosphate