Does the lactose carrier of Escherichia coli function as a monomer?

Abstract

The purified lactose carrier of Escherichia coli (product of the lacY gene) is shown to be a monomer in detergent micelles of dodecyl-O-β-D-maltoside. The negative-dominant phenotype of mutant carriers (lacY-d mutants) could not be verified by measurements of the rate of galactoside transport in lacY+/Y-d diploid strains. It is proposed that the membrane-embedded carrier functions as a monomer in galactoside-H+ symport. © 1983.