Disruption of the glycine cleavage system enables Sinorhizobium fredii USDA257 to form nitrogen-fixing nodules on agronomically improved North American soybean cultivars.

The symbiosis between Sinorhizobium fredii USDA257 and soybean [Glycine max (L.) Merr.] exhibits a high degree of cultivar specificity.

Y4xP, an open reading frame located in a type III protein secretion system locus of Sinorhizobium fredii USDA257 and USDA191, encodes cysteine synthase.

Sinorhizobium fredii USDA257, a soybean symbiont, exports several nodulation outer proteins (Nops) into the rhizosphere. These proteins, which are exported by a type III secretion system (TTSS), have a pivotal role in host-specific nodulation. The entire TTSS of S.

NopB, a soybean cultivar-specificity protein from Sinorhizobium fredii USDA257, is a type III secreted protein.

The type III secretion system (TTSS) of plant- and animal-pathogenic bacteria is involved in translocation of virulence factors into the host cell cytosol where they modulate cellular processes. Sinorhizobium fredii USDA257 is a gram-negative soil bacterium that forms nitrogen-fixing nodules on specific soybean cultivars (Glycine max (L.) Merr.