Perosamine (or GDP-perosamine) is a

mannose Mannose is a sugar monomer of the aldohexose series of carbohydrates. It is a C-2 epimer of glucose. Mannose is important in human metabolism, especially in the glycosylation of certain proteins. Several congenital disorders of glycosylation a ...

-derived 4-aminodeoxysugar produced by some bacteria.

Biological role

''N''-acetyl-perosamine is found in the ''O''-antigen of

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...

bacteria such as ''

Vibrio cholerae ''Vibrio cholerae'' is a species of Gram-negative, facultative anaerobe and comma-shaped bacteria. The bacteria naturally live in brackish or saltwater where they attach themselves easily to the chitin-containing shells of crabs, shrimps, and ot ...

'' ''O''1, ''E. coli'' ''O''157:H7 and ''

Caulobacter crescentus ''Caulobacter crescentus'' is a Gram-negative, oligotrophic bacterium widely distributed in fresh water lakes and streams. The taxon is more properly known as ''Caulobacter vibrioides'' (Henrici and Johnson 1935). ''C. crescentus'' is an impo ...

'' CB15. The sugar is also found in

perimycin Perimycin, also known as aminomycin and fungimycin, is polyene antibiotic produced by ''Streptomyces coelicolor'' var. aminophilus. The compound exhibits antifungal properties. __TOC__ Composition Perimycin is produced naturally as a mixture of t ...

, an

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy, ...

produced by the

Gram-positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bac ...

organism ''

Streptomyces ''Streptomyces'' is the largest genus of Actinomycetota and the type genus of the family Streptomycetaceae. Over 500 species of ''Streptomyces'' bacteria have been described. As with the other Actinomycetota, streptomycetes are gram-positive, ...

coelicolor'' var. aminophilus.

Biosynthesis

Its biosynthesis from

mannose-1-phosphate Mannose 1-phosphate is a molecule involved in glycosylation. See also * Congenital disorder of glycosylation * Mannose-6-phosphate Mannose-6-phosphate (M6P) is a molecule bound by lectin in the immune system. M6P is converted to fructose 6-ph ...

follows a pathway similar to that of

colitose Colitose is a mannose-derived 3,6-dideoxysugar produced by certain bacteria. It is a constituent of the lipopolysaccharide. It is the enantiomer of abequose. Biological role Colitose is found in the O-antigen of certain Gram-negative bacteria s ...

, but is different in that it is aminated and does not undergo 3-OH deoxygenation or C-5 epimerization.

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

GDP-perosamine synthase is a PLP-dependent

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...

that transfers a nitrogen from

glutamate Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can syn ...

to the 4-keto position of GDP-4-keto-6-deoxymannose during the biosynthesis of GDP-perosamine.

References

{{Reflist Hexosamines Deoxy sugars