Perosamine Explained

Perosamine (or GDP-perosamine) is a mannose-derived 4-aminodeoxysugar produced by some bacteria.

Biological role

N-acetyl-perosamine is found in the O-antigen of Gram-negative bacteria such as Vibrio cholerae O1, E. coli O157:H7 and Caulobacter crescentus CB15.^[1] The sugar is also found in perimycin, an antibiotic produced by the Gram-positive organism Streptomyces coelicolor var. aminophilus.^[2]

Biosynthesis

Its biosynthesis from mannose-1-phosphate follows a pathway similar to that of colitose, but is different in that it is aminated and does not undergo 3-OH deoxygenation or C-5 epimerization.^[3]

GDP-4-keto-6-deoxymannose-4-aminotransferase (GDP-perosamine synthase)

GDP-perosamine synthase is a PLP-dependent enzyme that transfers a nitrogen from glutamate to the 4-keto position of GDP-4-keto-6-deoxymannose during the biosynthesis of GDP-perosamine.^[1]

Notes and References

1. Samuel G, Reeves P . Biosynthesis of O-antigens: genes and pathways involved in nucleotide sugar precursor synthesis and O-antigen assembly . Carbohydr. Res. . 338 . 23 . 2503–19 . 2003 . 14670712 . 10.1016/j.carres.2003.07.009.
2. Pawlak J, Sowiński P, Borowski E, Gariboldi P . Stereostructure of perimycin A . J. Antibiot. . 48 . 9 . 1034–8 . September 1995 . 7592049 . 10.7164/antibiotics.48.1034 . free .
3. Albermann C, Piepersberg W . Expression and identification of the RfbE protein from Vibrio cholerae O1 and its use for the enzymatic synthesis of GDP-D-perosamine . Glycobiology . 11 . 8 . 655–61 . August 2001 . 11479276 . 10.1093/glycob/11.8.655. free .