Mechanistic insights into the LsrK kinase required for autoinducer-2 quorum sensing activation.

ABSTRACT: In enteric bacteria, the kinase LsrK catalyzes the phosphorylation of the C5-hydroxyl group in the linear form of 4,5-dihydroxy-2,3-pentanedione (DPD), the precursor of the type II bacterial quorum sensing molecule (AI-2). This phosphorylation is required for AI-2 sequestration in the cytoplasm and subsequent derepression of AI-2-related genes necessary for quorum development. While LsrK is a critical enzyme within the DPD quorum sensing relay system, kinetic details of this kinase have yet to be reported. A continuous UV-vis spectrophotometric assay was developed that allowed steady-state kinetic analysis of LsrK to be undertaken with the substrates ATP and DPD. The data was most consistent with a rapid equilibrium ordered mechanism with ATP binding first: kcat (7.4 ± 0.6 s(-1)), Km,ATP (

SUBMITTER: Zhu J 

PROVIDER: S-EPMC3736694 | biostudies-literature | 2013 May

REPOSITORIES: biostudies-literature