Examination of conformational dynamics of AdiC transporter with fluorescence-polarization microscopy.

ABSTRACT: To understand the mechanism underlying the ability of individual AdiC molecules to transport arginine and agmatine, we used a recently developed high-resolution single-molecule fluorescence-polarization microscopy method to investigate conformation-specific changes in the emission polarization of a bifunctional fluorophore attached to an AdiC molecule. With this capability, we resolved AdiC's four conformations characterized by distinct spatial orientations in the absence or presence of the two substrates, and furthermore, each conformation's two energetic states, totaling 24 states. From the lifetimes of individual states and state-to-state transition probabilities, we determined 60 rate constants characterizing the transitions and 4 KD values characterizing the interactions of AdiC's two

SUBMITTER: Lewis JH 

PROVIDER: S-EPMC11841622 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature