Part of the ABC transporter complex TcyJLN involved in L-cystine import (PubMed:25139244, PubMed:20351115, PubMed:25837721, PubMed:26350134). This high affinity cystine transporter is involved in resistance to oxidative stress by forming a L-cysteine/L-cystine shuttle system with the EamA transporter, which exports L-cysteine as reducing equivalents to the periplasm to prevent the cells from oxidative stress. Exported L-cysteine can reduce the periplasmic hydrogen peroxide to water, and then generated L-cystine is imported back into the cytoplasm via the TcyJLN complex (PubMed:20351115, PubMed:25837721). Functions at low cystine concentrations (PubMed:26350134). The system can also transport L-cysteine, diaminopimelic acid (DAP), djenkolate, lanthionine, D-cystine, homocystine, and it mediates accumulation of the toxic compounds L-selenaproline (SCA) and L-selenocystine (SeCys) (PubMed:25139244, PubMed:26350134). Could also facilitate threonine efflux (PubMed:28911185). Responsible for energy coupling to the transport system (Probable). ATP + H2O + L-cystine(out) = ADP + H(+) + L-cystine(in) + phosphate ATP + D-cystine(out) + H2O = ADP + D-cystine(in) + H(+) + phosphate The TcyJLN system is inhibited by L-cystine, L-cysteine, DL-2,6-diaminopimelic acid and L-cystathionine, and is stimulated by D-cysteine. The complex is composed of two ATP-binding proteins (TcyN), two transmembrane proteins (TcyL) and a solute-binding protein (TcyJ). Expression is induced by H(2)O(2). Disruption of the gene decreases uptake of cystine. Belongs to the ABC transporter superfamily.