Studies on active site mutants of P. falciparum adenylosuccinate synthetase: insights into enzyme catalysis and activation

Biochimica Et Biophysica Acta
Sonali MehrotraHemalatha Balaram

Abstract

Adenylosuccinate synthetase catalyzes a reversible reaction utilizing IMP, GTP and aspartate in the presence of Mg²+ to form adenylosuccinate, GDP and inorganic phosphate. Comparison of similarly liganded complexes of Plasmodium falciparum, mouse and Escherichia coli AdSS reveals H-bonding interactions involving nonconserved catalytic loop residues (Asn429, Lys62 and Thr307) that are unique to the parasite enzyme. Site-directed mutagenesis has been used to examine the role of these interactions in catalysis and structural organization of P. falciparum adenylosuccinate synthetase (PfAdSS). Mutation of Asn429 to Val, Lys62 to Leu and Thr307 to Val resulted in an increase in K(m) values for IMP, GTP and aspartate, respectively along with a 5 fold drop in the k(cat) value for N429V mutant suggesting the role of these residues in ligand binding and/or catalysis. We have earlier shown that the glycolytic intermediate, fructose 1,6 bisphosphate, which is an inhibitor of mammalian AdSS is an activator of the parasite enzyme. Enzyme kinetics along with molecular docking suggests a mechanism for activation wherein F16BP seems to be binding to the Asp loop and inducing a conformation that facilitates aspartate binding to the enzyme active...Continue Reading

References

Nov 1, 1977·Archives of Biochemistry and Biophysics·G D Markham, G H Reed
Jan 1, 1983·Current Topics in Cellular Regulation·M M StaytonH J Fromm
Nov 22, 1996·The Journal of Biological Chemistry·C KangH J Fromm
Feb 12, 2000·Journal of Molecular Biology·L PradeR Fonne-Pfister
Dec 14, 2001·The Journal of Biological Chemistry·Zhenglin HouRichard B Honzatko
Jan 10, 2002·The Journal of Biological Chemistry·Andrea GorrellHerbert J Fromm
May 11, 2002·The Journal of Biological Chemistry·Cristina V IancuRichard B Honzatko
Jan 20, 2004·Journal of Molecular Biology·K EaazhisaiM R N Murthy
Oct 27, 2004·Molecular and Biochemical Parasitology·Jayalakshmi RamanHemalatha Balaram

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Citations

Nov 26, 2015·Nature Communications·Lionel BallutNushin Aghajari
May 28, 2019·Molecular Microbiology·Lakshmeesha Kempaiah NagappaHemalatha Balaram

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