Translations:Pyridoxal phosphate/15/en
PLP-enzymes
PLP is retained in the active site not only thanks to the lysine, but also thanks to the interaction of the phosphate group and a phosphate binding pocket and to a lesser extent thanks to base stacking of the pyridine ring with an overhanging aromatic residue, generally tyrosine (which may also partake in the acid–base catalysis). Despite the limited requirements for a PLP binding pocket, PLP enzymes belong to only five different families. These families do not correlate well with a particular type of reaction. The five families are classified as fold types followed by a Roman numeral.
- Fold Type I — aspartate aminotransferase family
- Fold Type II — tryptophan synthase family
- Fold Type III — alanine racemase family (TIM-barrel)
- Fold Type IV — D-amino acid aminotransferase family
- Fold Type V — glycogen phosphorylase family