Beta-galactoside transport in E. coli: a functional dissection of lac permease.
The polytopic membrane protein lac permease harnesses energy from the electrochemical H+ gradient to transport beta-galactosidases against a concentration gradient. Although high-resolution structural information is still lacking, the permease is thought to possess 12 membrane-spanning alpha-helical segments. Various experimental strategies, including site-directed mutagenesis, have been employed to probe the function of this membrane protein at the molecular level.
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Howard Hughes Medical Institute, Molecular Biology Institute, Los Angeles, CA 90024-1570.
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D000595:Amino Acid Sequence; D001692:Biological Transport; D004926:Escherichia coli / Q000201:enzymology* / Q000378:metabolism; D029968:Escherichia coli Proteins; D005697:Galactosides / Q000378:metabolism*; D006027:Glycosides / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000502:physiology*; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins; D027981:Symporters
D029968:Escherichia coli Proteins; D005697:Galactosides; D006027:Glycosides; C050221:LacY protein, E coli; D026901:Membrane Transport Proteins; D009004:Monosaccharide Transport Proteins; D027981:Symporters; C007816:beta-galactoside; C021499:lactose permease