Identification of galacturonic acid-1-phosphate kinase, a new member of the GHMP kinase superfamily in plants, and comparison with galactose-1-phosphate kinase.

ABSTRACT: The process of salvaging sugars released from extracellular matrix, during plant cell growth and development, is not well understood, and many molecular components remain to be identified. Here we identify and functionally characterize a unique Arabidopsis gene encoding an alpha-d-galacturonic acid-1-phosphate kinase (GalAK) and compare it with galactokinase. The GalAK gene appeared to be expressed in all tissues implicating that glycose salvage is a common catabolic pathway. GalAK catalyzes the ATP-dependent conversion of alpha-d-galacturonic acid (d-GalA) to alpha-d-galacturonic acid-1-phosphate (GalA-1-P). This sugar phosphate is then converted to UDP-GalA by a UDP-sugar pyrophosphorylase as determined by a real-time (1)H NMR-based assay. GalAK is a distinct member of the GHMP kinase fa

SUBMITTER: Yang T 

PROVIDER: S-EPMC2755877 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature