Figure 2
Structure of human KHK-A. (a) A topology diagram of the human ketohexokinase subunit. The α-helices are shown as cylinders and the β-strands as arrows. Each secondary-structural element is labelled with its starting and ending sequence number. The secondary-structural elements were defined using DSSP (Kabsch & Sander, 1983). (b) A ribbon diagram representing the overall fold of the KHK subunit. The core domain of the monomer is comprised of a nine-stranded β-sheet flanked on both sides by α-helices. The four-stranded β-sheet formed by β2, β6, β7 (cyan) and β3 (yellow) extends away from the core domain, leaving a cleft for the active site. β3 is separated into two strands, β3a and β3b, by a bend at residues 32–33 that lies at the C-terminal end of β-strand β3a. |