Page Banner

United States Department of Agriculture

Agricultural Research Service

Title: Characterization and Expression of Udp-Sugar Pyrophosphorylase from Arabidopsis

Authors
item Litterer, Lynn - UNIVERSITY OF MINNESOTA
item Plaisance, Kathryn - UNIVERSITY OF MINNESOTA
item Schnurr, Judy
item Storey, Kathleen - UNIVERSITY OF MINNESOTA
item Gronwald, John
item Somers, David - UNIVERSITY OF MINNESOTA

Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 31, 2005
Publication Date: July 18, 2005
Citation: Litterer, L.A., Plaisance, K.L., Schnurr, J.A., Storey, K.K., Gronwald, J.W., Somers, D.A. 2005. Characterization and expression of UDP-sugar pyrophosphorylase from Arabidopsis [abstract]. American Society of Plant Biologists Annual Meeting. Abstract No. 579.

Technical Abstract: A bioinformatics approach was used to clone and characterize a UDP-sugar pyrophosphorylase (AtUSP) from Arabidopsis thaliana that has high activity with UDP-glucuronic acid (UDP-GlcA). AtUSP is predicted to be a cytosolic protein that belongs to a pyrophosphorylase family distantly related to the UDP-glucose and UDP-N-acetylglucosamine pyrophosphorylase families. The recombinant enzyme expressed in E. coli had high activity with GlcA-1-P, glucose-1-P, and galactose-1-P but very low activity with N-acetylglucosamine-1-P, fucose-1-P, mannose-1-P, inositol-1-P, or glucose-6-P. The enzyme had a molecular weight of 70 kDa, was activated by magnesium and preferred UTP as co-substrate. AtUSP had apparent Km values for GlcA-1-P, glucose-1-P, and UTP of 0.13 mM, 0.42 mM, and 0.14 mM, respectively. In the reverse direction, the apparent Km values for UDP-GlcA, UDP-glucose, and pyrophosphate were 0.56 mM, 0.72 mM, and 0.15 mM, respectively. Evaluation of AtUSP expression by semiquantitative RT-PCR and enzyme activity assays indicated that both transcript and enzyme are widely expressed.

Last Modified: 9/10/2014
Footer Content Back to Top of Page