Structural basis for the enhanced thermal stability of alcohol dehydrogenase mutants from the mesophilic bacterium Clostridium beijerinckii: contribution of salt bridging.

ABSTRACT: Previous research in our laboratory comparing the three-dimensional structural elements of two highly homologous alcohol dehydrogenases, one from the mesophile Clostridium beijerinckii (CbADH) and the other from the extreme thermophile Thermoanaerobacter brockii (TbADH), suggested that in the thermophilic enzyme, an extra intrasubunit ion pair (Glu224-Lys254) and a short ion-pair network (Lys257-Asp237-Arg304-Glu165) at the intersubunit interface might contribute to the extreme thermal stability of TbADH. In the present study, we used site-directed mutagenesis to replace these structurally strategic residues in CbADH with the corresponding amino acids from TbADH, and we determined the effect of such replacements on the thermal stability of CbADH. Mutations in the intrasubunit ion pair regi

SUBMITTER: Bogin O 

PROVIDER: S-EPMC2373725 | biostudies-literature | 2002 Nov

REPOSITORIES: biostudies-literature