The domain within your query sequence starts at position 311 and ends at position 425; the E-value for the PGM_PMM_III domain shown below is 6.9e-31.

PSDSLAIIAANLSCIPYFRQMGVRGFGRSMPTSTALDRVAKSMKVPVYETPAGWRFFSNL
MDSGRCSLCGEESFGTGSDHLREKDGLWAVLVWLSIIAARKQSVEEIVRDHWAKY

PGM_PMM_III

PGM_PMM_III
PFAM accession number:PF02880
Interpro abstract (IPR005846):

The alpha-D-phosphohexomutase superfamily is composed of four related enzymes, each of which catalyses a phosphoryl transfer on their sugar substrates: phosphoglucomutase (PGM), phosphoglucomutase/phosphomannomutase (PGM/PMM), phosphoglucosamine mutase (PNGM), and phosphoacetylglucosamine mutase (PAGM) [ (PUBMED:10506283) ]. PGM ( EC 5.4.2.2 ) converts D-glucose 1-phosphate into D-glucose 6-phosphate, and participates in both the breakdown and synthesis of glucose [ (PUBMED:15299905) ]. PGM/PMM ( EC 5.4.2.2 ; EC 5.4.2.8 ) are primarily bacterial enzymes that use either glucose or mannose as substrate, participating in the biosynthesis of a variety of carbohydrates such as lipopolysaccharides and alginate [ (PUBMED:16595672) (PUBMED:14725765) ]. Both PNGM ( EC 5.4.2.3 ) and PAGM ( EC 5.4.2.10 ) are involved in the biosynthesis of UDP-N-acetylglucosamine [ (PUBMED:10913078) (PUBMED:11004509) ].

Despite differences in substrate specificity, these enzymes share a similar catalytic mechanism, converting 1-phospho-sugars to 6-phospho-sugars via a biphosphorylated 1,6-phospho-sugar. The active enzyme is phosphorylated at a conserved serine residue and binds one magnesium ion; residues around the active site serine are well conserved among family members. The reaction mechanism involves phosphoryl transfer from the phosphoserine to the substrate to create a biophosphorylated sugar, followed by a phosphoryl transfer from the substrate back to the enzyme [ (PUBMED:15238632) ].

The structures of PGM and PGM/PMM have been determined, and were found to be very similar in topology. These enzymes are both composed of four domains and a large central active site cleft, where each domain contains residues essential for catalysis and/or substrate recognition. Domain I contains the catalytic phosphoserine, domain II contains a metal-binding loop to coordinate the magnesium ion, domain III contains the sugar-binding loop that recognises the two different binding orientations of the 1- and 6-phospho-sugars, and domain IV contains a phosphate-binding site required for orienting the incoming phospho-sugar substrate.

This entry represents domain III found in alpha-D-phosphohexomutase enzymes. This domain has a 3-layer alpha/beta/alpha topology.

GO process:carbohydrate metabolic process (GO:0005975)
GO function:intramolecular transferase activity, phosphotransferases (GO:0016868)

This is a PFAM domain. For full annotation and more information, please see the PFAM entry PGM_PMM_III