BIOCHEMICAL-IDENTIFICATION OF A LIPOPROTEIN WITH MALTOSE-BINDING ACTIVITY IN THE THERMOACIDOPHILIC GRAM-POSITIVE BACTERIUM ALICYCLOBACILLUS-ACIDOCALDARIUS

Growth of the thermoacidophilic Gram-positive bacterium Alicyclobacill us acidocaldarius strain ATCC 27009 on maltose resulted in the increas ed production of a protein with apparent molecular mass of 40 kDa. By metabolic labelling with C-14-palmitic acid, the 40-kDa protein was id entified as a lipoprotein. The protein exhibited maltose-binding activ ity at pH 3.5, as demonstrated by chromatography on cross-linked amylo se. Partial amino acid sequence analysis revealed that the 40-kDa prot ein coresponds to the product of an open reading frame downstream from the amylase gene (amy) that displays similarity to enterobacterial ma ltose-binding proteins.