An enzyme that catalyzes the formation of N-5'-phosphoribosylanthranilic acid from anthranilate and phosphoribosylpyrophosphate, the first step in tryptophan synthesis in E. coli. It exists in a complex with ANTHRANILATE SYNTHASE in bacteria. EC 2.4.2.18.

Synonyms: Pyrophosphorylase, Phosphoribosylanthranilate, Phosphoribosylanthranilate Pyrophosphorylase, PR Transferase, Anthranilate, EC 2.4.2.18, Anthranilate PR Transferase, Anthranilate Phosphoribosyltransferase, N-(5-Phospho-D-ribosyl)-anthranilate:pyrophosphate phospho-alpha-D-ribosyltransferase, Phosphoribosyltransferase, Anthranilate