117e
From Proteopedia
|
THE R78K AND D117E ACTIVE SITE VARIANTS OF SACCHAROMYCES CEREVISIAE SOLUBLE INORGANIC PYROPHOSPHATASE: STRUCTURAL STUDIES AND MECHANISTIC IMPLICATIONS
Overview
We have solved the structure of two active-site variants of soluble, inorganic pyrophosphatases (PPase), R78K and D117K, at resolutions of 1.85, and 2.15 A and R-factors of 19.5% and 18.3%, respectively.In the R78K, variant structure, the high-affinity phosphate group (P1) is missing, consistent with the wild-type structure showing a bidentate interaction, between P1 and Arg78, and solution data showing a decrease in P1 affinity, in the variant. The structure explains why the mutation affects P1 and, pyrophosphate binding much more than would be expected by the loss of one, hydrogen bond: Lys78 forms an ion-pair with Asp71, precluding an, interaction with P1. The R78K variant also provides the first direct, evidence that the low-affinity phosphate group (P2) can adopt the, structure that ... [(full description)]
About this Structure
117E is a [Single protein] structure of sequence from [Saccharomyces cerevisiae] with MN and PO4 as [ligands]. Full crystallographic information is available from [OCA].
Reference
The R78K and D117E active-site variants of Saccharomyces cerevisiae soluble inorganic pyrophosphatase: structural studies and mechanistic implications., Tuominen V, Heikinheimo P, Kajander T, Torkkel T, Hyytia T, Kapyla J, Lahti R, Cooperman BS, Goldman A, J Mol Biol. 1998 Dec 18;284(5):1565-80. PMID:9878371
Page seeded by OCA on Sun Oct 28 19:31:22 2007
