label: (R)-carnitine:4-(trimethylammonio)butanoate antiporter activity
label_lc: (r)-carnitine:4-(trimethylammonio)butanoate antiporter activity
description: "Enables the transfer of a solute or solutes from one side of a membrane to the other according to the reaction: (R)-carnitine(out) + 4-(trimethylammonio)butanoate(in) = (R)-carnitine(in) + 4-(trimethylammonio)butanoate(out)."