1uxh
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LARGE IMPROVEMENT IN THE THERMAL STABILITY OF A TETRAMERIC MALATE DEHYDROGENASE BY SINGLE POINT MUTATIONS AT THE DIMER-DIMER INTERFACE
OverviewOverview
The stability of tetrameric malate dehydrogenase from the green, phototrophic bacterium Chloroflexus aurantiacus (CaMDH) is at least in, part determined by electrostatic interactions at the dimer-dimer, interface. Since previous studies had indicated that the thermal stability, of CaMDH becomes lower with increasing pH, attempts were made to increase, the stability by removal of (excess) negative charge at the dimer-dimer, interface. Mutation of Glu165 to Gln or Lys yielded a dramatic increase in, thermal stability at pH 7.5 (+23.6 -- + 23.9 degrees C increase in, apparent t(m)) and a more moderate increase at pH 4.4 (+4.6 -- + 5.4, degrees C). The drastically increased stability at neutral pH was achieved, without forfeiture of catalytic performance at low temperatures. The, crystal ... [(full description)]
About this StructureAbout this Structure
1UXH is a [Single protein] structure of sequence from [Chloroflexus aurantiacus] with NAD and FMR as [ligands]. Active as [Malate dehydrogenase], with EC number [1.1.1.37]. Structure known Active Site: AC1. Full crystallographic information is available from [OCA].
ReferenceReference
Large improvement in the thermal stability of a tetrameric malate dehydrogenase by single point mutations at the dimer-dimer interface., Bjork A, Dalhus B, Mantzilas D, Sirevag R, Eijsink VG, J Mol Biol. 2004 Aug 27;341(5):1215-26. PMID:15321717
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