Tobar I, et al. (2008) Relevance of Arg457 for the nucleotide affinity of Saccharomyces cerevisiae phosphoenolpyruvate carboxykinase. Int J Biochem Cell Biol 40(9):1883-9
Abstract: Phosphoenolpyruvate carboxykinases catalyze one of the first steps in the biosynthesis of glucose and depending on the enzyme origin, preferentially use adenine or guanine nucleotides as substrates. The Saccharomyces cerevisiae enzyme has a marked preference for ADP (or ATP) over other nucleotides. Homology models of the enzyme in complex with ADP or ATP show that the guanidinium group of Arg457 is close to the adenine base, suggesting that this group might be involved in the stabilization of the nucleotide substrate. To evaluate this we have performed the mutation Arg457Met, replacing the positively charged guanidinium group by a neutral residue. The mutated enzyme retained the structural characteristics of the wild-type protein. Fluorescence titration experiments showed that mutation causes a loss of 1.7kcalmol(-1) in the binding affinity of the enzyme for ADPMn. Similarly, kinetic analyses of the mutated enzyme showed 50-fold increase in K(m) for ADPMn, with minor alterations in the other kinetic parameters. These results show that Arg457 is an important factor for nucleotide binding by S. cerevisiae PEP carboxykinase.
| Status: Published | Type: Journal Article | PubMed ID: 18346928 |
Topics addressed in this paper
- To find other papers on a gene and topic, click on the colored ball in the appropriate box.
- displays other papers with information about that topic for that gene.
- displays other papers in SGD that are associated with that topic.
The topic is addressed in these papers but does not describe a specific gene or chromosomal feature.
- To go to the Locus page for a gene, click on the gene name.
| Topics | Genes linked to topics |
|---|---|
| PCK1 | |
| Mutants/Phenotypes | |
| Primary Literature | |
| Protein Physical Properties | |
| Protein Sequence Features | |
| Substrates/Ligands/Cofactors | |




