Clustering of genes in : Cloning of the maltose permease gene and expression from the divergent intergenic region between the maltose permease and maltase genes

Abstract

Hansenula polymorpha uses maltase to grow on maltose and sucrose. Inspection of genomic clones of H. polymorpha showed that the maltase gene HPMAL1 is clustered with genes corresponding to Saccharomyces cerevisiae maltose permeases and MAL activator genes orthologues. We sequenced the H. polymorpha maltose permease gene HPMAL2 of the cluster. The protein (582 amino acids) deduced from the HPMAL2 gene is predicted to have eleven transmembrane domains and shows 39-57% identity with yeast maltose permeases. The identity of the protein is highest with maltose permeases of Debaryomyces hansenii and Candida albicans. Expression of the HPMAL2 in a S. cerevisiae maltose permease-negative mutant CMY1050 proved functionality of the permease protein encoded by the gene. HPMAL1 and HPMAL2 genes are divergently positioned similarly to maltase and maltose permease genes in many yeasts. A two-reporter assay of the expression from the HPMAL1-HPMAL2 intergenic region showed that expression of both genes is coordinately regulated, repressed by glucose, induced by maltose, and that basal expression is higher in the direction of the permease gene.

A Novel High-Affinity Sucrose Transporter Is Required for Virulence of the Plant Pathogen Ustilago maydis

“…The Srt1 protein has 12 predicted transmembrane domains (TMDs [18]) and a large extracellular loop between TMD1 and TMD2 (Figure 1C), a typical structural feature of previously characterized fungal and plant hexose transporters [8],[19]. Sequence comparisons revealed a moderate similarity (less than 30% identity) of Srt1 to a large group of transport proteins (Figure S3) that includes numerous well-characterized high-affinity monosaccharide transporters from plants and fungi as well as some low-affinity maltose transporters from Saccharomyces cerevisiae [20]–[22], Pichia angusta (synonym: Hansenula polymorpha [23]), or Schizosaccharomyces pombe [24]. Phylogenetic analyses revealed that Srt1 is most closely related to a small group of so-far uncharacterized proteins (Figure S3).…”

“…Thus, the affinity of Srt1 for sucrose is several 100-fold to several 1,000-fold higher than that of the fungal maltose/maltotriose transporters [24],[28]. Moreover, its affinity is also much higher than that of higher plant sucrose transporters (20-fold to more than 200-fold), which catalyze sucrose uptake with K M values in the millimolar range [23].…”

Hansenula polymorpha maltase gene promoter with sigma 70-like elements is feasible for Escherichia coli-based biotechnological applications: Expression of three genomic levansucrase genes of Pseudomonas syringae pv. tomato

“…In our previous work, we have described the MAL gene cluster that is responsible for the utilization of maltose and sucrose in Hansenula polymorpha [1,2]. Cloning of the maltase gene (HpMAL1) of the above mentioned cluster showed that the promoter (P MAL1 ) of this gene was also functional in Escherichia coli, as high maltase activity in HpMAL1-possessing transformants was observed [3].…”

Characterization and expression analysis of a maltose-utilizing (MAL) cluster in Aspergillus oryzae

“…In addition to Saccharomyces yeasts, there are some reports that describe a cluster of three genes encoding a maltose permease, an a-glucosidase (maltase), and a transcription factor in Hansenula polymorpha (Viigand et al, 2005;Viigand and Alamäe, 2007), or a clustering of maltase and maltose permease genes in Torulaspora delbrueckii (Alves-Araújo et al, 2004) and Kluyveromyces lactis (Fairhead and Dujon, 2006). Thus far, however, there are no reports concerning such a cluster in filamentous fungi, and hence this is the first report that characterizes the functional maltose-utilization cluster in filamentous fungi.…”

“…B, BamHI; H, HindIII; K, KpnI; P, PstI; S, SalI; Sc, ScaI; and X, XhoI. For comparison, the organization of the MAL clusters from yeasts S. cerevisiae (retrieved from the Saccharomyces genome database (http://www.yeastgenome.org/)) and H. polymorpha (P. angusta)(Viigand et al, 2005) is also shown with that of the MAL homolog cluster present in A. oryzae genome. In the MAL cluster of H. polymorpha, HPMAL1, HPMAL2, and HPMAL3 code for maltase, maltose permease, and putative MAL activator, respectively.…”