Regulative interactions of the osmosensing C-terminal domain in the trimeric glycine betaine transporter BetP from Corynebacterium glutamicum.
Activation of the osmoregulated trimeric betaine transporter BetP from Corynebacterium glutamicum was shown to depend mainly on the correct folding and integrity of its 55 amino acid long, partly alpha-helical C-terminal domain. Reorientation of the three C-terminal domains in the BetP trimer indicates different lipid-protein and protein-protein interactions of the C-terminal domain during osmoregulation. A regulation mechanism is suggested where this domain switches the transporter from the inactive to the active state. Interpretation of recently obtained electron and X-ray crystallography data of BetP led to a structure-function based model of C-terminal molecular switching involved in osmoregulation.
Institute of Biochemistry, University of Cologne, D-50674 Cologne, Germany.
Reinhard
R
Krämer
Christine
C
Ziegler
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000502:physiology*; D002352:Carrier Proteins / Q000502:physiology*; D048230:Corynebacterium glutamicum / Q000378:metabolism; D008055:Lipids / Q000494:pharmacology; D008565:Membrane Proteins / Q000502:physiology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017510:Protein Folding / Q000187:drug effects; D017434:Protein Structure, Tertiary; D027981:Symporters; D014882:Water-Electrolyte Balance / Q000502:physiology*
D001426:Bacterial Proteins; C101652:BetP protein, Corynebacterium glutamicum; D002352:Carrier Proteins; D008055:Lipids; D008565:Membrane Proteins; D027981:Symporters