This domain is found N terminal to Pfam:PF07238, therefore named PilZN. Proteins which contain PilZN (also known as YcgR) are know to interact with the flagellar switch-complex proteins FliG and FliM. This interaction results in a reduction of torque generation and induces CCW motor bias [3]. This domain exhibits a similar structur as PilZ domains comprising a beta-barrel fold but lack the C-terminal alpha-helix [4].

1: The PilZ domain is a receptor for the second messenger c-di-GMP: the PilZ domain protein YcgR controls motility in enterobacteria. Ryjenkov DA, Simm R, Romling U, Gomelsky M; J Biol Chem. 2006;281:30310-30314. PMID:16920715

2: Second messenger-mediated adjustment of bacterial swimming velocity. Boehm A, Kaiser M, Li H, Spangler C, Kasper CA, Ackermann M, Kaever V, Sourjik V, Roth V, Jenal U; Cell. 2010;141:107-116. PMID:20303158

3: The c-di-GMP binding protein YcgR controls flagellar motor direction and speed to affect chemotaxis by a "backstop brake" mechanism. Paul K, Nieto V, Carlquist WC, Blair DF, Harshey RM; Mol Cell. 2010;38:128-139. PMID:20346719

4: Structural Conservation and Diversity of PilZ-Related Domains. Galperin MY, Chou SH; J Bacteriol. 2020; [Epub ahead of print] PMID:31740493