The YGR194c (XKS1) gene encodes the xylulokinase from the budding yeast Saccharomyces cerevisiae

Abstract

We report the finding of a Saccharomyces cerevisiae gene necessary for growth in culture media with D-xylulose as the sole carbon source. This gene corresponds to the YGR194c open reading frame that we have previously described, and it is renamed now XKS1. Data bank comparisons of the protein encoded by the XKS1 gene showed significant homology with different xylulokinases, indicating a possible role in xylulose phosphorylation. The wild-type gene in a centromeric plasmid complemented defective growth of xks1 S. cerevisiae mutant strains in xylulose. By contrast, overexpression negatively influenced cell growth in this carbon source. z 1998 Federation of European Microbiological Societies. Published by Elsevier Science B.V.

Development of Efficient Xylose Fermentation in Saccharomyces cerevisiae: Xylose Isomerase as a Key Component

“…This keto-isomer of xylose is phosphorylated to d-xylulose-5-phosphate by xylulokinase (XKS1, [57]) and subsequently metabolised via the non-oxidative part of the pentose phosphate pathway and glycolysis. It is therefore logical that strategies for converting d-xylose into d-xylulose are an exhaustively studied topic in the quest for alcoholic fermentation of d-xylose by S. cerevisiae.…”

Mutants defective in secretory/vacuolar pathways in the EUROFAN collection of yeast disruptants

“…Those that did included ygl196wD, hoc1D, ygr262D cells, and xks1D cells, deficient in a xylulokinase (Rodriguez-Pena et al, 1998). YGL196w encodes a small protein (18 kDa), with a homologue in Schizosaccharomyces pombe.…”

Bioethanol a Microbial Biofuel Metabolite; New Insights of Yeasts Metabolic Engineering

“…As early as 1988, D-xylulokinase sequences from S. cerevisiae and Pachysolen tannophilus have been described [162][163][164]. In the yeast genome project, the complete S. cerevisiae gene XK was identified [165]. However, the XK enzyme, which was described by Ho and Tsao in 1993, was found to be inactive [164,166].…”

“…In native S. cerevisiae, D-xylulokinase is not expressed meaningfully; however, it is crucial for xylulose metabolism as the ∆XK mutants have a defect to grow on xylulose [163]. Simultaneously, the XK overexpression can cause a defect on the growth of the yeast strain on xylulose [165]. Over unlimited access to xylulose, the severe toxicity accomplished with XK overexpression can be due to depletion in ATP [168][169][170].…”