Baqiyatallah University of Medical Sciences Journal of Applied Biotechnology Reports 2322-1186 1 1 2014 03 01 Effects of missense R84Q mutation on human Pyrroline-5-carboxylate synthase enzyme properties, an in-silico analysis 11 16 68937 EN Maryam Zare Department of Biology, Payame Noor University, Avaj, Iran Faranak Hadi Department of Biology, Faculty of Science, Lorestan University, Khoramabad, Iran Zarrin Minuchehr Industrial and Environmental Biotechnology Department, National Institute of Genetic Engineering & Biotechnology (NIGEB), Tehran, Iran Jafar Amani Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran Ali Hatef Salmanian Department of Plant Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran 0000-0002-9984-7441 Journal Article 2014 02 15 Mammalian ∆-(1)-Pyrroline-5-carboxylate synthase (P5CS) enzyme catalyzes the coupled phosphorylation and reduction-conversion of glutamate to ∆-(1)-pyrroline-5-carboxylate (P5C), a critical step in the proline, ornithine, citrulline and arginine biosynthesis. In plants and mammals, P5CS consists of two separate enzymatic domains: N-terminal γ-glutamyl kinase (γ-GK) and C-terminal γ-glutamyl phosphate reductase (γ–GPR). Hyperammonemia has been reported as a new inborn disorder, with a range of clinical symptoms which is associated with a reduced synthesis of proline, ornithine, citruline and arginine. A missense mutation, R84Q, which alters the conserved residue in γ-GK domain, is responsible for this disorder. In this study using <em>in-silico</em> approaches as a new bioinformatics method, sequence analysis was performed and the tertiary structure of γ-GK domain of human P5CS, which includes the R84Q missense mutation, was predicted and the mutation effects on structural and functional features of P5CS enzyme were analyzed. Our analysis showed that this substitution has an affect on the molecular surface accessibility and total energy of the modeled structure. We conclude that this mutation results in a reduced activity of P5CS enzyme and an impaired synthesis of these amino acids. https://www.biotechrep.ir/article_68937_fb9d83e7ff505a7c71d64894ccf2305a.pdf