1qgx
From Proteopedia
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X-RAY STRUCTURE OF YEAST HAL2P
Overview
The product of the yeast HAL2 gene (Hal2p) is an in vivo target of sodium, and lithium toxicity and its overexpression improves salt tolerance in, yeast and plants. Hal2p is a metabolic phosphatase which catalyses the, hydrolysis of 3'-phosphoadenosine-5'-phosphate (PAP) to AMP. It is, the, prototype of an evolutionarily conserved family of PAP phosphatases and, the engineering of sodium insensitive enzymes of this group may contribute, to the generation of salt-tolerant crops. We have solved the crystal, structure of Hal2p in complex with magnesium, lithium and the two products, of PAP hydrolysis, AMP and Pi, at 1.6 A resolution. A functional screening, of random mutations of the HAL2 gene in growing yeast generated forms of, the enzyme with reduced cation sensitivity. Analysis of these mutants, defined a salt bridge (Glu238 ellipsis Arg152) and a hydrophobic bond, (Va170 ellipsis Trp293) as important framework interactions determining, cation sensitivity. Hal2p belongs to a larger superfamily of, lithium-sensitive phosphatases which includes inositol monophosphatase., The hydrophobic interaction mutated in Hal2p is conserved in this, superfamily and its disruption in human inositol monophosphatase also, resulted in reduced cation sensitivity.
About this Structure
1QGX is a Single protein structure of sequence from Saccharomyces cerevisiae with MG, PO4, SO4, AMP and BME as ligands. Active as 3'(2'),5'-bisphosphate nucleotidase, with EC number 3.1.3.7 Full crystallographic information is available from OCA.
Reference
X-ray structure of yeast Hal2p, a major target of lithium and sodium toxicity, and identification of framework interactions determining cation sensitivity., Albert A, Yenush L, Gil-Mascarell MR, Rodriguez PL, Patel S, Martinez-Ripoll M, Blundell TL, Serrano R, J Mol Biol. 2000 Jan 28;295(4):927-38. PMID:10656801
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