This family consists of Type 3 secretion system (T3SS) stator protein, previously known as nodulation protein NolV, from different Rhizobium species [1]. The function of this family is unclear, however, it has been suggested that this protein is a component of the T3SS, which is used to inject bacterial effector proteins into eukaryotic host cells.

1: Molecular cloning and characterization of a sym plasmid locus that regulates cultivar-specific nodulation of soybean by Rhizobium fredii USDA257. Meinhardt LW, Krishnan HB, Balatti PA, Pueppke SG; Mol Microbiol 1993;9:17-29. PMID:8412662