ABC transporter substrate-binding protein PnrA-like
Proteins containing this domain were originally annotated as basic membrane lipoproteins. However, several proteins containing this domain were later predicted as ABC transporter substrate-binding proteins, such as PnrA (also known as TmpC or TP0319) and RfuA (also known as Tpn38 or TP0298) from Treponema pallidum. PnrA transports purine nucleosides, while RfuA transports riboflavin. Proteins containing this domain also include Med from Bacillus subtilis. Med was annotated as a transcriptional activator protein that regulates comK. This domain can also found at the N terminus of glutamate receptor-like proteins from Dictyostelium (slime mold).