protein N-acetylglucosaminyltransferase complex

Definition

Target type: cellularcomponent

A protein complex capable of protein N-acetylglucosaminyltransferase activity, the addition of nucleotide-activated sugars onto the polypeptide according to reaction: UDP-N-acetyl-D-glucosamine + protein = UDP + 4-N-(N-acetyl-D-glucosaminyl)-protein. The complex has different compositions in different species: In mammals it is often a homotrimer, in bacteria a heterotetramer of 2 different subunits. [PMID:15247246]

The N-acetylglucosaminyltransferase (GnT) complex is a multi-protein assembly found in the Golgi apparatus, a cellular organelle responsible for protein modification and sorting. This complex is essential for the synthesis of N-glycans, which are complex sugar structures attached to proteins. The GnT complex consists of multiple glycosyltransferases, each with a specific catalytic function in the assembly of N-glycans. The individual proteins within the complex are interconnected through a series of protein-protein interactions, forming a dynamic structure that allows for efficient and precise glycosylation. The GnT complex functions as a platform for the sequential transfer of sugar residues to protein substrates. The catalytic core of the complex comprises multiple GnT enzymes, each with a distinct substrate specificity, which dictates the specific N-glycan structure that is synthesized. These enzymes are assisted by other proteins that play regulatory roles in the complex, such as chaperones and lectins. Chaperones ensure proper folding and stability of the complex while lectins recognize specific glycan structures and facilitate their assembly. The GnT complex exhibits remarkable plasticity and its composition can vary depending on the cell type and developmental stage. This flexibility allows for the production of diverse N-glycan structures with specific functions, ranging from protein folding and trafficking to cell adhesion and immune recognition.'
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Proteins (1)

Compounds (6)