The gene glpK, encoding glycerol kinase of Thermus aquaticus has been identified [Biosci. Biotechnol. Biochem., 62 (1998) 2375-2381]. In the present work, the nucleotide sequence of glpFK operon and the gene glpF encoding glycerol facilitator were determined. T. aquaticus GlpF was predicted to contain 272 amino acids with six putative transmembrane segments and two half-membrane-spanning segments that contained the motif Asn-Pro-Ala, respectively. The amino acid residues involved in the discrimination of glycerol were deduced to be Trp44, Tyr182, and Arg188.