Aerobactin
Encyclopedia
Aerobactin is a bacteria
l iron chelating agent (siderophore
) found in E. coli
. It is a virulence factor
enabling E. coli to sequester iron
in iron-poor environments, for example, the urinary tract
.
Aerobactin is synthesised
from the oxidation of lysine
, as catalysed by the aerobactin synthase
enzyme. The gene
for this enzyme is found in the aerobactin operon
, which is roughly 8 kilobases long and contains 5 or more genes in total.
Yersinia pestis
contains genes relating to aerobactin, but they have been inactivated by a frameshift mutation
, thus Y. pestis is no longer able to synthesise aerobactin.
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
l iron chelating agent (siderophore
Siderophore
Siderophores are small, high-affinity iron chelating compounds secreted by grasses and microorganisms such as bacteria and fungi...
) found in E. coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
. It is a virulence factor
Virulence factor
Virulence factors are molecules expressed and secreted by pathogens that enable them to achieve the following:* colonization of a niche in the host...
enabling E. coli to sequester iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
in iron-poor environments, for example, the urinary tract
Urinary system
The urinary system is the organ system that produces, stores, and eliminates urine. In humans it includes two kidneys, two ureters, the bladder and the urethra.-Kidney:...
.
Aerobactin is synthesised
Biosynthesis
Biosynthesis is an enzyme-catalyzed process in cells of living organisms by which substrates are converted to more complex products. The biosynthesis process often consists of several enzymatic steps in which the product of one step is used as substrate in the following step...
from the oxidation of lysine
Lysine
Lysine is an α-amino acid with the chemical formula HO2CCH4NH2. It is an essential amino acid, which means that the human body cannot synthesize it. Its codons are AAA and AAG....
, as catalysed by the aerobactin synthase
Aerobactin synthase
In enzymology, an aerobactin synthase is an enzyme that catalyzes the chemical reactionThe 4 substrates of this enzyme are ATP, citrate, N6-acetyl-N6-hydroxy-L-lysine, and H2O, whereas its 3 products are ADP, phosphate, and aerobactin....
enzyme. The gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
for this enzyme is found in the aerobactin operon
Operon
In genetics, an operon is a functioning unit of genomic DNA containing a cluster of genes under the control of a single regulatory signal or promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo trans-splicing to create...
, which is roughly 8 kilobases long and contains 5 or more genes in total.
Yersinia pestis
Yersinia pestis
Yersinia pestis is a Gram-negative rod-shaped bacterium. It is a facultative anaerobe that can infect humans and other animals....
contains genes relating to aerobactin, but they have been inactivated by a frameshift mutation
Frameshift mutation
A frameshift mutation is a genetic mutation caused by indels of a number of nucleotides that is not evenly divisible by three from a DNA sequence...
, thus Y. pestis is no longer able to synthesise aerobactin.
Other homologues
- Rhizobactin from SinorhizobiumSinorhizobiumSinorhizobium/Ensifer is a genus of nitrogen-fixing bacteria , two of which have been sequenced.-Etymology:...
- Alcaligin from BordetellaBordetellaBordetella is a genus of small , Gram-negative coccobacilli of the phylum proteobacteria. Bordetella species, with the exception of B. petrii, are obligate aerobes as well as highly fastidious, or difficult to culture. Three species are human pathogens ; one of these Bordetella is a genus of small...