The initiation of GTP hydrolysis by the G-domain of FeoB: insights from a transition-state complex structure.

ABSTRACT: The polytopic membrane protein FeoB is a ferrous iron transporter in prokaryotes. The protein contains a potassium-activated GTPase domain that is essential in regulating the import of iron and conferring virulence to many disease-causing bacteria. However, the mechanism by which the G-domain of FeoB hydrolyzes GTP is not well understood. In particular, it is not yet known how the pivotal step in GTP hydrolysis is achieved: alignment of a catalytic water molecule. In the current study, the crystal structure of the soluble domains from Streptococcus thermophilus FeoB (NFeoB(St)) in complex with the activating potassium ion and a transition-state analogue, GDP⋅AlF(4) (-), reveals a novel mode of water alignment involving contacts with the protein backbone only. In parallel to the structural

SUBMITTER: Ash MR 

PROVIDER: S-EPMC3153494 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature