TrpP is a bacterial transmembrane protein that is probably involved in tryptophan uptake. Its expression is regulated by tryptophan-activated RNA-binding regulatory protein (TRAP) [1].

1: A Bacillus subtilis gene of previously unknown function, yhaG, is translationally regulated by tryptophan-activated TRAP and appears to be involved in tryptophan transport. Sarsero JP, Merino E, Yanofsky C; J Bacteriol. 2000;182:2329-2331. PMID:10735881