Human NUDT22 Is a UDP-Glucose/Galactose Hydrolase Exhibiting a Unique Structural Fold

Structure. 2018 Feb 6;26(2):295-303.e6. doi: 10.1016/j.str.2018.01.004.

Abstract

Human NUDT22 belongs to the diverse NUDIX family of proteins, but has, until now, remained uncharacterized. Here we show that human NUDT22 is a Mg2+-dependent UDP-glucose and UDP-galactose hydrolase, producing UMP and glucose 1-phosphate or galactose 1-phosphate. We present the structure of human NUDT22 alone and in a complex with the substrate UDP-glucose. These structures reveal a partially conserved NUDIX fold domain preceded by a unique N-terminal domain responsible for UDP moiety binding and recognition. The NUDIX domain of NUDT22 contains a modified NUDIX box identified using structural analysis and confirmed through functional analysis of mutants. Human NUDT22's distinct structure and function as a UDP-carbohydrate hydrolase establish a unique NUDIX protein subfamily.

Keywords: NUDIX; NUDT22; UDP-galactose; UDP-glucose; hydrolase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Galactosephosphates / metabolism*
  • Glucosephosphates / metabolism*
  • Humans
  • Phosphoric Diester Hydrolases / metabolism*
  • Protein Folding

Substances

  • Galactosephosphates
  • Glucosephosphates
  • galactose-1-phosphate
  • glucose-1-phosphate
  • Phosphoric Diester Hydrolases
  • UDP-galactose hydrolase