In vivo cross-linking supports a head-to-tail mechanism for regulation of the plant plasma membrane P-type H+-ATPase [Membrane Biology]

In this study, we used in vivo cross-linking experiments with a photoreactive unnatural amino acid, p-benzoylphenylalanine, and tandem MS to obtain direct evidence that the C-terminal regulatory domain interacts with amino acids located within the N-terminal actuator domain. Our observations are consistent with a mechanism in which intermolecular, rather than intramolecular, interactions are involved. Our model invokes a “head-to-tail” organization of ATPase monomers in which the C-terminal domain of one ATPase molecule interacts with the actuator domain of another ATPase molecule. This model serves to explain why cross-linked peptides are found only in dimers and trimers, and it is consistent with prior studies suggesting that within the membrane the protein can be organized as homopolymers, including dimers, trimers, and hexamers.

Source: Journal of Biological Chemistry - November 2, 2018 Category: Chemistry Authors: Thao T. Nguyen, Grzegorz Sabat, Michael R. Sussman Tags: Plant Biology Source Type: research