malQ mutants of Escherichia coli lacking amylomaltase cannot grow on maltose. They express the maltose system constitutively and are sensitive to maltose when grown on another carbon source. In an attempt to isolate a multicopy suppressor that would result in growth on maltose, we transformed a malQ mutant with a gene bank of E. coli DNA which had been digested with Sau3a and cloned in pBR322. ...

The fission yeast Schizosaccharomyces pombe secretes the extracellular maltase Agl1, which hydrolyzes maltose into glucose, thereby utilizing maltose as a carbon source. Whether other maltases contribute to efficient utilization of maltose and how Agl1 expression is regulated in response to switching of carbon sources are unknown. In this study, we show that three other possible maltases and th...

The interaction of the radioactively labeled purified maltose-binding protein of Escherichia coli with membrane vesicles was studied. The maltose-binding protein bound specifically to the vesicles, in the presence of maltose, on few sites. Under conditions in which a potential was imposed across the membrane, the specific binding was (i) increased, (ii) dependent on maltose, and (iii) abolished...

Growth and metabolite formation were studied in oxygen-limited chemostat cultures of Saccharomyces cerevisiae CBS 8066 and Candida utilis CBS 621 growing on glucose or maltose at a dilution rate of 0.1 h-1. With either glucose or maltose S. cerevisiae could be grown under dual limitation of oxygen and sugar. Respiration and alcoholic fermentation occurred simultaneously and the catabolite fluxe...

Efficient fermentation of maltotriose is a desired property of Saccharomyces cerevisiae for brewing. In a standard wort, maltotriose is the second most abundant sugar, and slower uptake leads to residual maltotriose in the finished product. The limiting factor of sugar metabolism is its transport, and there are conflicting reports on whether a specific maltotriose permease exists or whether the...

Maltose-binding protein (MBP), which is encoded by the malE gene, is the maltose chemoreceptor of Escherichia coli, as well as an essential component of the maltose uptake system. Maltose-loaded MBP is thought to initiate a chemotactic response by binding to the tar gene product, the signal transducer Tar, which is also the aspartate chemoreceptor. To study the interaction of MBP with Tar, we s...

Maltose-binding protein (MBP) is essential for maltose transport and chemotaxis in Escherichia coli. To perform these functions it must interact with two sets of cytoplasmic membrane proteins, the MalFGK transport complex and the chemotactic signal transducer Tar. MBP is present at high concentrations, on the order of 1 mM, in the periplasm of maltose-induced or malTc constitutive cells. To det...

Important biotechnological processes depend on the efficient fermentation by Saccharomyces cerevisiae yeasts of starch hydrolysates rich in maltose and maltotriose. The rate-limiting step for fermentation of these α-glucosides is the transport across the plasma membrane of the cells. In order to contribute to a better understanding of maltose and maltotriose metabolism by S. cerevisiae, we anal...

We have created a molecular switch by the in vitro recombination of nonhomologous genes and subjecting the recombined genes to evolutionary pressure. The gene encoding TEM1 beta-lactamase was circularly permuted in a random fashion and subsequently randomly inserted into the gene encoding Escherichia coli maltose binding protein. From this library, a switch (RG13) was identified in which its be...

Trehalose synthase (TreS) was thought to catalyze flux from maltose to trehalose, a precursor of essential trehalose mycolates in mycobacterial cell walls. However, we now show, using a genetic approach, that TreS is not required for trehalose biosynthesis in Mycobacterium smegmatis, whereas two alternative trehalose-biosynthetic pathways (OtsAB and TreYZ) are crucial. Consistent with this dire...