Solution structure of the low-molecular-weight protein tyrosine phosphatase from Tritrichomonas foetus reveals a flexible phosphate binding loop.

ABSTRACT: Eukaryotic low-molecular-weight protein tyrosine phosphatases (LMW PTPs) contain a conserved serine, a histidine with an elevated pKa, and an active site asparagine that together form a highly conserved hydrogen bonding network. This network stabilizes the active site phosphate binding loop for optimal substrate binding and catalysis. In the phosphatase from the bovine parasite Tritrichomonas foetus (TPTP), both the conserved serine (S37) and asparagine (N14) are present, but the conserved histidine has been replaced by a glutamine residue (Q67). Site-directed mutagenesis, kinetic, and spectroscopic experiments suggest that Q67 is located near the active site and is important for optimal catalytic activity. Kinetic experiments also suggest that S37 participates in the active site/hydrogen

SUBMITTER: Gustafson CL 

PROVIDER: S-EPMC2253298 | biostudies-literature | 2005 Oct

REPOSITORIES: biostudies-literature