Maltose and maltodextrin transport in the thermoacidophilic gram-positive bacterium Alicyclobacillus acidocaldarius is mediated by a high-affinity transport system that includes a maltose binding protein tolerant to low pH.

ABSTRACT: We have studied the uptake of maltose in the thermoacidophilic gram-positive bacterium Alicyclobacillus acidocaldarius, which grows best at 57 degrees C and pH 3.5. Under these conditions, accumulation of [(14)C]maltose was observed in cells grown with maltose but not in those grown with glucose. At lower temperatures or higher pH values, the transport rates substantially decreased. Uptake of radiolabeled maltose was inhibited by maltotetraose, acarbose, and cyclodextrins but not by lactose, sucrose, or trehalose. The kinetic parameters (K(m) of 0.91 +/- 0.06 microM and V(max) ranging from 0.6 to 3.7 nmol/min/mg of protein) are consistent with a binding protein-dependent ATP binding cassette (ABC) transporter. A corresponding binding protein (MalE) that interacts with maltose with high aff

SUBMITTER: Hulsmann A 

PROVIDER: S-EPMC94774 | biostudies-literature | 2000 Nov

REPOSITORIES: biostudies-literature