Possible important pair of acidic residues in vesicular acetylcholine transporter.

Invariant E309 is in contact with critical and invariant D398 in a three-dimensional homology model of vesicular acetylcholine transporter (VAChT, TC 2.A.1.

Mutational and bioinformatics analysis of proline- and glycine-rich motifs in vesicular acetylcholine transporter.

The vesicular acetylcholine transporter (VAChT) contains six conserved sequence motifs that are rich in proline and glycine. Because these residues can have special roles in the conformation of polypeptide backbone, the motifs might have special roles in conformational changes during transport. Using published bioinformatics insights, the amino acid sequences of the 12 putative, helical, transmembrane segments of wild-type and mutant VAChTs were analyzed for propensity to form non-alpha-helical conformations and molecular notches.

Acetylcholine binding site in the vesicular acetylcholine transporter.

This study sought primarily to locate the acetylcholine (ACh) binding site in the vesicular acetylcholine transporter (VAChT). The design of the study also allowed us to locate residues linked to (a) the binding site for the allosteric inhibitor vesamicol and (b) the rates of the two transmembrane reorientation steps of a transport cycle. In more characterized proteins, ACh is known to be bound in part through cation-pi solvation by tryptophan, tyrosine, and phenylalanine residues.