Yop-YscD-ppl is the periplasmic domain of Yop proteins like YscD from Proteobacteria. YscD forms part of the inner membrane component of the bacterial type III secretion injectosome apparatus [1,2].

1: Analysis of virC, an operon involved in the secretion of Yop proteins by Yersinia enterocolitica. Michiels T, Vanooteghem JC, Lambert de Rouvroit C, China B, Gustin A, Boudry P, Cornelis GR; J Bacteriol 1991;173:4994-5009. PMID:1860816

2: In situ structural analysis of the Yersinia enterocolitica injectisome. Kudryashev M, Stenta M, Schmelz S, Amstutz M, Wiesand U, Castano-Diez D, Degiacomi MT, Munnich S, Bleck CK, Kowal J, Diepold A, Heinz DW, Dal Peraro M, Cornelis GR, Stahlberg H; Elife. 2013;2:e00792. PMID:23908767