Tinkering with transporters: periplasmic binding protein-dependent maltose transport in E. coli.
Periplasmic binding protein-dependent transport systems represent a common mechanism for nutrient and ion uptake in bacteria. As a group, these systems are related to one another and to other transporters of both prokaryotes and eukaryotes, based on sequence similarity within an ATP-binding subunit and overall structural organization. These transporters probably all use energy derived from ATP to pump substrates across membranes. Although there is considerable information about the sequences and identity of the transporters, there is little information about how they work. That is, where do ligands bind? Where do the subunits or domains interact with one another? How is the energy of nucleotide binding and/or hydrolysis converted to conformational changes? In order to address these questions we have taken a genetic approach that involves studying mutant forms of a transporter. Rather than study mutations that result in complete loss of function, the study of mutations which perturb or alter the normal function of the transporter in a defined manner has provided a limited insight into how the answers to these questions may be obtained.
Shuman
H A
HA
Department of Microbiology, College of Physicians and Surgeons, Columbia University, New York, New York 10032.
Panagiotidis
C H
CH
D018528:ATP-Binding Cassette Transporters; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003550:Cystic Fibrosis; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D006801:Humans; D008320:Maltose / Q000378:metabolism*; D058619:Maltose-Binding Proteins; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D008961:Models, Structural; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins; D033902:Periplasmic Binding Proteins; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; C505032:CFTR protein, human; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; C461619:MalE protein, E coli; C079123:MalG protein, E coli; D058619:Maltose-Binding Proteins; D008565:Membrane Proteins; D009004:Monosaccharide Transport Proteins; D033902:Periplasmic Binding Proteins; C461599:maltose transport system, E coli; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D008320:Maltose