Diversity of transport mechanisms: common structural principles.
Traditionally, prokaryotic solute transport systems are classified into major groups based on the energetic requirement of the transport process. These include the secondary transporters that are driven by a proton or sodium motive force, and the ATP-binding cassette (ABC) primary transporters, which use the hydrolysis of ATP to fuel transport. These transporters are specified by entirely different architectures of polypeptides. Recently, transport systems have been discovered that are composed of combinations of distinct functional modules of both secondary and ABC transporters. These findings indicate that during evolution the combination of integral membrane transport proteins with either a periplasmic solute-binding protein or a cytosolic ATPase, or both, have resulted in distinct classes of transporters with unique architectures and properties.
Dept of Microbiology and Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9751 NN Haren, the Netherlands.
A J
AJ
Driessen
B P
BP
Rosen
W N
WN
Konings
D000251:Adenosine Triphosphatases / Q000378:metabolism; D001693:Biological Transport, Active; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D019143:Evolution, Molecular; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008954:Models, Biological; D011387:Prokaryotic Cells / Q000378:metabolism; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary
D002352:Carrier Proteins; D008565:Membrane Proteins; D000251:Adenosine Triphosphatases