Disease relevance of otsA

• We have now expressed the otsA and otsB genes of Escherichia coli, which encode trehalose biosynthetic enzymes, in human primary fibroblasts using a recombinant adenovirus vector [1].
• Thus, otsA/otsB induction and trehalose synthesis are activated during cold shock (as well as during heat shock) and play an important role in resistance of E. coli (and probably other organisms) to low temperatures [2].
• Trehalose biosynthesis in Thermus thermophilus RQ-1: biochemical properties of the trehalose-6-phosphate synthase and trehalose-6-phosphate phosphatase [3].
• Overproduction of trehalose: heterologous expression of Escherichia coli trehalose-6-phosphate synthase and trehalose-6-phosphate phosphatase in Corynebacterium glutamicum [4].

High impact information on otsA

• This induction required the varsigma factor, RpoS, but was independent of the major cold-shock protein, CspA. otsA/B mRNA was much more stable at 16 degrees C than at 37 degrees C and contained a "downstream box," characteristic of cold-inducible mRNAs [2].
• Its active site pocket is highly similar to four retaining GT-B glycosyltransferases (trehalose-6-phosphate synthase, glycogen synthase, glycogen and maltodextrin phosphorylases) strongly suggesting a common evolutionary origin and catalytic mechanism for these enzymes [5].
• Expression of escherichia coli otsA in a Saccharomyces cerevisiae tps1 mutant restores trehalose 6-phosphate levels and partly restores growth and fermentation with glucose and control of glucose influx into glycolysis [6].
• We have performed a molecular cloning of the otsBA genes, and we present evidence that they constitute an operon encoding trehalose-6-phosphate phosphatase and trehalose-6-phosphate synthase [7].
• A gene, otsP, necessary for the synthesis of the biosynthetic trehalose-6-phosphate phosphatase, is located at min 42 closely linked to otsA/B the structural genes for the trehalose-6-phosphate synthase [8].

Biological context of otsA

• There is another gene locus near 84 min on the chromosome, that we termed otsR, which is involved in the regulation of otsA/B and possibly otsP [8].
• Significantly, photosynthetic capacity (CO(2) assimilation at varying light and CO(2), and quantum yield of PSII electron transport) per unit leaf area and per leaf dry weight were increased in lines of N. tabacum transformed with the E. coli gene otsA, which encodes trehalose phosphate synthase [9].

Other interactions of otsA

• Primer extension analysis showed only one transcription start point upstream from otsB and one upstream from otsA, regardless of the growth conditions tested [10].

Analytical, diagnostic and therapeutic context of otsA

• The start codons of the otsB and otsA genes were established by N-terminal sequence determination of the proteins [10].
• In contrast, we introduced the cDNA sequence of the tps1 gene from Saccharomyces cerevisiae, which has 54% identity with the gene otsA, as one of the templates in shuffling PCR [11].

References