ABC-type (ATP-binding cassette-type) transporter, characterized by the presence of two similar ATP-binding domains/proteins and two integral membrane domains/proteins. A bacterial enzyme that interacts with an extracytoplasmic substrate binding protein and mediates the high affinity import of trace cystine. The enzyme from Escherichia coli K-12 can import both isomers of cystine and a variety of related molecules including djenkolate, lanthionine, diaminopimelate and homocystine.
