The R163K mutant of human thymidylate synthase is stabilized in an active conformation: structural asymmetry and reactivity of cysteine 195.

@article{Gibson2008TheRM,
  title={The R163K mutant of human thymidylate synthase is stabilized in an active conformation: structural asymmetry and reactivity of cysteine 195.},
  author={L. M. Gibson and L. Lovelace and L. Lebioda},
  journal={Biochemistry},
  year={2008},
  volume={47 16},
  pages={
          4636-43
        }
}
Loop 181-197 of human thymidylate synthase (hTS) populates two conformational states. In the first state, Cys195, a residue crucial for catalytic activity, is in the active site (active conformer); in the other conformation, it is about 10 A away, outside the active site (inactive conformer). We have designed and expressed an hTS variant, R163K, in which the inactive conformation is destabilized. The activity of this mutant is 33% higher than that of wt hTS, suggesting that at least one-third… Expand
Variants of human thymidylate synthase with loop 181–197 stabilized in the inactive conformation
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The very low activity of M190K as compared to another mutant with a charged residue in this position, M190E, suggests that the protein is trapped in an inactive state that does not equilibrate easily with the active conformer. Expand
Human thymidylate synthase with loop 181–197 stabilized in an inactive conformation: Ligand interactions, phosphorylation, and inhibition profiles
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In summary, inactive‐stabilized mutants differ from hTS in thermal stability and response to substrates and PDPA, providing the first indication of physiological relevance for conformational switching. Expand
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Structures of human thymidylate synthase R163K with dUMP, FdUMP and glutathione show asymmetric ligand binding.
TLDR
A new crystal form of the R163K variant of human TS with five subunits per asymmetric part of the unit cell, all with loop 181-197 in the active conformation, is reported, indicating that this form should facilitate high-throughput analysis of hTS complexes with drug candidates. Expand
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The active–inactive transition of human thymidylate synthase: Targeted molecular dynamics simulations
TLDR
Target molecular dynamics simulations of the transitions between active and inactive states of hTS suggest that blocking of AS loop rotation by ligands binding in the large cavity between the loops could be one way to stabilize inactive hTS and inhibit the enzyme. Expand
Analysis of mRNA recognition by human thymidylate synthase
TLDR
A combination of X-ray crystallography, RNA mutagenesis and site-specific cross-linking studies are used to investigate the molecular recognition of TS mRNA by the hTS enzyme. Expand
Biomolecular study of human thymidylate synthase conformer-selective inhibitors: New chemotherapeutic approach
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Structural analysis of a shrimp thymidylate synthase reveals species-specific interactions with dUMP and raltitrexed
Thymidylate synthase (TS) is a key enzyme in the de novo biosynthesis of thymidine monophosphate, serving as a well-known drug target in chemotherapy against cancers and infectious diseases.Expand
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