Site-directed mutagenesis of two aromatic residues lining the active site pocket of the yeast Ltp1

• Published in: Biochimica et biophysica acta Vol. 1770; no. 5; pp. 753 - 762
• Main Authors: Paoli, Paolo, Modesti, Alessandra, Magherini, Francesca, Gamberi, Tania, Caselli, Anna, Manao, Giampaolo, Raugei, Giovanni, Camici, Guido, Ramponi, Giampietro
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.05.2007
• Subjects: Alanine - metabolism; Amino Acid Substitution; Amino Acids, Aromatic - chemistry; Amino Acids, Aromatic - genetics; Aromatic residue; Binding Sites; Catalysis; Hydrogen-Ion Concentration; Kinetics; LMW-PTP; Ltp1; Models, Molecular; Mutagenesis; Mutagenesis, Site-Directed; Phosphorylation; Protein Tyrosine Phosphatases - chemistry; Protein Tyrosine Phosphatases - genetics; PTP; Saccharomyces cerevisiae - chemistry; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae Proteins - chemistry; Saccharomyces cerevisiae Proteins - genetics; Substrate Specificity - genetics; Tryptophan - chemistry; Tryptophan - genetics; Tyrosine - chemistry; Tyrosine - genetics; Tyrosine phosphorylation; Yeast; CD; Aromatic residue; Yeast; Mutagenesis; Tyrosine phosphorylation; PTK; LMW; GST; pNPP; LMW-PTP; PTP; Ltp1

We mutated Trp 134 and Tyr 135 of the yeast LMW-PTP to explore their catalytic roles, demonstrating that the mutations of Trp 134 to Tyr or Ala, and Tyr 135 to Ala, all interfere with the formation of the phosphorylenzyme intermediate, a phenomenon that can be seen by the decrease in the kinetic con...