Disease relevance of RKI1

• The C-terminal domain resembles ribose-5-phosphate isomerase from Escherichia coli with a similar location of the active site [1].

High impact information on RKI1

• Pea chloroplastic phosphoribulokinase and yeast phosphoriboisomerase partition independently of one another in a two-phase polyethyleneglycol, dextran system, but apparent interaction is seen when ribose-5-phosphate is added to the two-phase system [2].
• Ribose-5-phosphate isomerase A has an important role in sugar metabolism by interconverting ribose-5-phosphate and ribulose-5-phosphate [3].
• On the basis of the conserved amino acids an alignment of the amino acid sequence of ribose-5-phosphate isomerase from yeast with those of the enzyme from mouse, spinach and Escherichia coli is presented [4].
• The molecular mass of the subunit and the identified N-terminal sequence of 33 amino acids fits well the 258 amino acid protein encoded by the S. cerevisiae RKI open reading frame, which was characterized previously only by increasing specific activities of ribose-5-phosphate isomerase in cells after cloning the gene [4].
• Synthesis of [32P]ADPribulose from [32P]NAD+ by the combined activities of commercial NAD+ glycohydrolase and phosphoriboisomerase allowed us to use it as a labeled internal standard throughout the procedure of purification from trichloroacetic acid extracts of human red blood cells [5].

Biological context of RKI1

• Unexpectedly, haploid rki1 deletion mutants are not viable [6].
• Functional expression of RKI1 was demonstrated following an increase of gene dosage in the haploid rki1 deletion mutant, which restored viability and specific D-ribose-5-phosphate ketol-isomerase activity [6].
• From an analysis of the plasmid harboured in A22t1, the RKI1 gene coding for ribose 5-phosphate ketol-isomerase and residing on chromosome no [7].
• The site of mutation on the RKI1 gene was identified as position 566 with a transition from guanine to adenine, resulting in amino acid substitution of Arg-189 with lysine [7].

Associations of RKI1 with chemical compounds

• We have cloned and characterized the two remaining unknown genes of the non-oxidative part of the pentose-phosphate pathway of Saccharomyces cerevisiae encoding the enzymes D-ribulose-5-phosphate 3-epimerase (Rpe1p) and D-ribose-5-phosphate ketol-isomerase (Rki1p) [6].

References