Phosphomannomutase

Phosphomannomutase (PMM) is an enzyme that plays a crucial role in the metabolic pathways of organisms. It is involved in the conversion of mannose-6-phosphate to mannose-1-phosphate, a key step in the synthesis of mannose-containing glycoproteins and glycolipids.

Function

Phosphomannomutase catalyzes the interconversion of mannose-6-phosphate and mannose-1-phosphate. This reaction is a critical step in the mannose biosynthetic pathway, which is essential for the production of N-linked and O-linked glycoproteins, as well as glycolipids.

Structure

Phosphomannomutase is a monomeric enzyme composed of a single polypeptide chain. The enzyme contains a phosphatase domain and a mutase domain, which are responsible for its catalytic activity. The structure of the enzyme is highly conserved among different species, indicating its essential role in cellular metabolism.

Clinical significance

Mutations in the genes encoding phosphomannomutase can lead to congenital disorder of glycosylation (CDG), a group of genetic disorders characterized by defective glycosylation of proteins and lipids. The most common form of CDG, CDG-Ia, is caused by mutations in the PMM2 gene, which encodes phosphomannomutase 2.

See also

• Mannose
• Glycosylation
• Congenital disorder of glycosylation