The maltose transporter MalFGK(2), together with the substrate-binding protein MalE, is one of the best-characterized ABC transporters. In the conventional model, MalE captures maltose in the periplasm and delivers the sugar to the transporter. Here, using nanodiscs and proteoliposomes, we instead find that MalE is bound with high-affinity to MalFGK2 to facilitate the acquisition of the sugar. ...

We have investigated the transport of maltose in a genetically defined maltose-fermenting strain of Saccharomyces cerevisiae carrying the MAL1 locus. Two kinetically different systems were identified: a high-affinity transporter with a Km of 4 mM and a low-affinity transporter with a Km of 70 to 80 mM. The high-affinity maltose transporter is maltose inducible and is encoded by the MAL11 (and/o...

High-affinity uptake into bacterial cells is mediated by a large class of periplasmic binding protein-dependent transport systems, members of the ATP-binding cassette superfamily. In the maltose transport system of Escherichia coli, the periplasmic maltose-binding protein binds its substrate maltose with high affinity and, in addition, stimulates the ATPase activity of the membrane-associated t...

The active transport of maltose in Escherichia coli requires the products of five genes. These include a water-soluble periplasmic maltose-binding protein, three cytoplasmic membrane proteins, and an outer membrane protein. In order to evaluate the role of the maltose-binding protein in active transport, a nonpolar internal deletion of the structural gene for the maltose-binding protein was con...

The Gram-positive Corynebacterium glutamicum efficiently metabolizes maltose by a pathway involving maltodextrin and glucose formation by 4-α-glucanotransferase, glucose phosphorylation by glucose kinases, and maltodextrin degradation via maltodextrin phosphorylase and α-phosphoglucomutase. However, maltose uptake in C. glutamicum has not been investigated. Interestingly, the presence of maltos...

Spores of the fungus Myrothecium verrucaria are cryptic to maltose and isomaltose. Induction of a transport system can be effected by several sugars whose order of effectiveness is: turanose > maltulose > sucrose > d-arabinose, d-fructose, nigerose, maltotriulose, kestose > melezitose, raffinose, nystose, and stachyose. The transport system is not specific to maltose and isomaltose, and it is a...

The effects of different levels of maltose on feed pellet water stability and nutrient leaching were studied. Five treatments, including control with three replicates with setup (0.0, 20, 25, 30 and 35%). Pellet leaching rates were used to indicate pellet water stability. The results show that the presence of maltose in the diets significantly improved pellet water stability (p<0.05), but the l...

The maltose/maltodextrin regulon of Escherichia coli consists of 10 genes which encode a binding protein-dependent ABC transporter and four enzymes acting on maltodextrins. All mal genes are controlled by MalT, a transcriptional activator that is exclusively activated by maltotriose. By the action of amylomaltase, we prepared uniformly labeled [(14)C]maltodextrins from maltose up to maltoheptao...

The E-domain of cyclodextrin glycosyltransferase (CGTase) (EC 2.4.1.19) from Bacillus circulans strain 251 is a putative raw starch binding domain. Analysis of the maltose-dependent CGTase crystal structure revealed that each enzyme molecule contained three maltose molecules, situated at contact points between protein molecules. Two of these maltoses were bound to specific sites in the E-domain...