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Carbohydrate uptake in Advenella mimigardefordensis strain DPN7 T is mediated by periplasmic sugar oxidation and a TRAP‐transport system
Author(s) -
Meinert Christina,
Senger Jana,
Witthohn Marco,
Wübbeler Jan Hendrik,
Steinbüchel Alexander
Publication year - 2017
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.13692
Subject(s) - periplasmic space , biochemistry , biology , complementation , sugar acids , gluconic acid , strain (injury) , galactose , mutant , sugar , escherichia coli , gene , anatomy
Summary In this study, we investigated an SBP (DctP Am ) of a tripartite ATP‐independent periplasmic transport system (TRAP) in Advenella mimigardefordensis strain DPN7 T . Deletion of dctP Am as well as of the two transmembrane compounds of the tripartite transporter, dctQ and dctM , impaired growth of A. mimigardefordensis strain DPN7 T , if cultivated on mineral salt medium supplemented with d ‐glucose, d ‐galactose, l ‐arabinose, d ‐fucose, d ‐xylose or d ‐gluconic acid, respectively. The wild type phenotype was restored during complementation studies of A. mimigardefordensis Δ dctP Am using the broad host vector pBBR1MCS‐5:: dctP Am . Furthermore, an uptake assay with radiolabeled [ 14 C(U)]‐ d ‐glucose clearly showed that the deletion of dctP Am , dctQ and dctM , respectively, disabled the uptake of this aldoses in cells of either mutant strain. Determination of K D performing thermal shift assays showed a shift in the melting temperature of DctP Am in the presence of d ‐gluconic acid ( K D 11.76 ± 1.3 µM) and the corresponding aldonic acids to the above‐mentioned carbohydrates d ‐galactonate ( K D 10.72 ± 1.4 µM), d ‐fuconic acid ( K D 13.50 ± 1.6 µM) and d ‐xylonic acid ( K D 8.44 ± 1.0 µM). The sugar (glucose) dehydrogenase activity (E.C.1.1.5.2) in the membrane fraction was shown for all relevant sugars, proving oxidation of the molecules in the periplasm, prior to transport.