Direct binding of benzoate derivatives to two chemoreceptors with Cache sensor domains in Halomonas titanicae KHS3

GASPEROTTI, ANA F.; KARINA HERRERA SEITZ, M.; BALMACEDA, ROCÍO S.; PROSA, LUCIANO M.; JUNG, KIRSTEN; STUDDERT, CLAUDIA A.

MOLECULAR MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2021 vol. 0 p. 1 - 12

0950-382X

Halomonas titanicae KHS3, isolated from a hydrocarbon-contaminated sea harbour in Argentina, is able to grow on aromatic hydrocarbons and displays chemotaxis towards those compounds.This behaviour might contribute to the efficiency of its degradation capacity. Using highthroughput screening, we identified two chemoreceptors (Htc1 and Htc2) that bind benzoatederivatives and other organic acids. Whereas Htc1 has a high affinity for benzoate (Kd 112 μM)and 2-hydroxybenzoate (Kd 83 μM), Htc2 binds 2-hydroxybenzoate with low affinity (Kd 3.25 mM)but also C3/C4 dicarboxylates. Both chemoreceptors are able to trigger a chemotactic responseof E. coli cells to the specific ligands. A H. titanicae htc1 mutant has reduced chemotaxistowards benzoate, and is complemented upon expression of the corresponding receptor. Bothchemoreceptors have a Cache-type sensor domain, double (Htc1) or single (Htc2), and theirability to bind aromatic compounds is reported here for the first time.