Part of the bacABCDEF operon responsible for the biosynthesis of the nonribosomally synthesized dipeptide antibiotic bacilysin, composed of L-alanine and L-anticapsin. Bacilysin is an irreversible inactivator of the glutaminase domain of glucosamine synthetase (PubMed:20052993). Catalyzes the reductive amination of the C2 ketone of tetrahydro-hydroxyphenylpyruvate (H4HPP), with L-Phe as an amino donor, to yield tetrahydrotyrosine (H4Tyr) diastereomer (PubMed:22765234). D-Phe is not an effective amino donor (PubMed:22765234). BacF associated to BacG converts 3E,7R- and 3Z,7R-ex-H2HPP to 2S,4R,7R- and 2S,4S,7R-H4Tyr, respectively. Given that bacilysin has the 2S,4S stereochemistry in its anticapsin moiety, it is likely that the 2S,4S-H4Tyr is the diastereomer used for the biosynthesis (PubMed:22765234). Antibiotic biosynthesis; bacilysin biosynthesis. Homodimer. The compound guanosine 5'-diphosphate 3'-diphosphate (ppGpp) is essential for the transcription of the bacABCDEF operon and BacG, and GTP regulates the transcription of both this operon and ywfH via the CodY-mediated regulation system. Belongs to the class-I pyridoxal-phosphate-dependent aminotransferase family.