4-aminobutanoyl-[BtrI ACP] + L-glutamate + ATP => 4-(gamma-L-glutamylamino)butanoyl-[BtrI ACP] + ADP + phosphate + H(+)
4-aminobutanoyl-[btri acp] + l-glutamate + atp => 4-(gamma-l-glutamylamino)butanoyl-[btri acp] + adp + phosphate + h(+)
4-aminobutanoyl-[BtrI ACP] + L-glutamate + ATP => 4-(gamma-L-glutamylamino)butanoyl-[BtrI ACP] + ADP + phosphate + H(+)
4-aminobutanoyl-[btri acp] + l-glutamate + atp => 4-(gamma-l-glutamylamino)butanoyl-[btri acp] + adp + phosphate + h(+)