Perosamine (or GDP-perosamine) is a

mannose Mannose is a sugar with the formula , which sometimes is abbreviated Man. It is one of the monomers of the aldohexose series of carbohydrates. It is a C-2 epimer of glucose. Mannose is important in human metabolism, especially in the glycosylatio ...

-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, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

bacteria such as ''

Vibrio cholerae ''Vibrio cholerae'' is a species of Gram-negative bacteria, Gram-negative, Facultative anaerobic organism, facultative anaerobe and Vibrio, comma-shaped bacteria. The bacteria naturally live in Brackish water, brackish or saltwater where they att ...

'' ''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 importa ...

'' 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 ...

, 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. The Gram stain is ...

organism ''

Streptomyces coelicolor ''Streptomyces albidoflavus'' is a bacterium species from the genus of ''Streptomyces'' which has been isolated from soil from Poland. ''Streptomyces albidoflavus'' produces dibutyl phthalate and streptothricins. Small noncoding RNA Bacteri ...

'' var. aminophilus.

Biosynthesis

Its biosynthesis from mannose-1-phosphate follows a pathway similar to that of

colitose Colitose is a mannose-derived dideoxy sugar, 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-negat ...

, 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 An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

that transfers a nitrogen from

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

to the 4-keto position of GDP-4-keto-6-deoxymannose during the

biosynthesis Biosynthesis, i.e., chemical synthesis occurring in biological contexts, is a term most often referring to multi-step, enzyme-Catalysis, catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthe ...

of GDP-perosamine.

References

{{Reflist Hexosamines Deoxy sugars