Isoleucine Binding and Regulation of <i>Escherichia coli</i> and <i>Staphylococcus aureus</i> Threonine Dehydratase (IlvA).

ABSTRACT: In Staphylococcus aureus, the branched-chain amino acid biosynthetic pathway provides essential intermediates for membrane biosynthesis. Threonine deaminase (IlvA) is the first enzyme in the pathway, and isoleucine feedback regulates the enzyme in Escherichia coli. These studies on E. coli IlvA (EcIlvA) introduced the concept of allosteric regulation. To investigate the regulation of S. aureus IlvA (SaIlvA), we first conducted additional studies on EcIlvA. The previously determined crystal structure of EcIlvA revealed a tetrameric assembly of protomers, each with catalytic and regulatory domains, but the structural basis of isoleucine regulation was not characterized. Here, we present the crystal structure of the EcIlvA regulatory domain bound to isoleucine, whi

SUBMITTER: Yun MK 

PROVIDER: S-EPMC12224302 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature