UniProt functional annotation for Q44493

UniProt code: Q44493.

Organism:		Azotobacter vinelandii.
Taxonomy:		Bacteria; Proteobacteria; Gammaproteobacteria; Pseudomonadales; Pseudomonadaceae; Azotobacter.
Function:		Converts beta-D-mannuronic acid (M) to alpha-L-guluronic acid (G), but introduces almost exclusively MG blocks, producing a polymer with non-gel-forming capacity. {ECO:0000269|PubMed:10212201}.
Catalytic activity:		Reaction=[(1->4)-beta-D-mannuronosyl](n) = [alginate](n); Xref=Rhea:RHEA:45572, Rhea:RHEA-COMP:11264, Rhea:RHEA-COMP:11270, ChEBI:CHEBI:58187, ChEBI:CHEBI:85311; EC=5.1.3.37; Evidence={ECO:0000269|PubMed:10212201};
Cofactor:		Name=Ca(2+); Xref=ChEBI:CHEBI:29108; Evidence={ECO:0000269|PubMed:10212201};
Activity regulation:		Inhibited by zinc. {ECO:0000269|PubMed:10212201}.
Biophysicochemical properties:		Kinetic parameters: Vmax=14.8 umol/min/mg enzyme {ECO:0000269|PubMed:10212201}; Note=kcat is 14 sec(-1). {ECO:0000269|PubMed:10212201}; pH dependence: Optimum pH is 6.5-7.0. {ECO:0000269|PubMed:10212201}; Temperature dependence: Optimum temperature is 37 degrees Celsius. {ECO:0000269|PubMed:10212201};
Pathway:		Glycan biosynthesis; alginate biosynthesis. {ECO:0000305}.
Subcellular location:		Secreted. Note=Probably exported via the hemolysin-type secretion pathway.
Developmental stage:		Produced in encysting cells.
Domain:		Composed of one catalytically active A module and one R module.
Miscellaneous:		Each enzyme of this family of C5 epimerases introduces its own characteristic sequence distribution of G-blocks in their substrates, explaining the extensive sequence variability of alginates. These alginates of varying composition have different physical properties and are necessary at different stages of the bacterium life cycle.
Similarity:		Belongs to the D-mannuronate C5-epimerase family. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.