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Siderophores Essay

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Siderophores
The identification of protein-protein interactions in cells of infectious bacteria cannot be fully understood without discussing how iron interacts between the bacteria and the host organisms (animals encompassing human). To circumvent the toxicity of iron within the human body, transferrin which is the human iron transporter protein keeps the concentration of free ferric ion at 10-24 M (Raymond et al., 3584). Astonishingly, pathogenic bacteria such as Pseudomonas aeruginosa should compete in conjunction with this thermodynamic limit to acquire iron from tissues or human serum (Raymond et al., 3584). It is impossible to underrate the importance of iron as the limiting nutrient in the development of bacteria. Excess iron …show more content…

It has been observed in some nitrogen-fixing bacteria (Clark, 13). Hydroxamate-type siderophore uses nitrogen atoms of oxazoline and thiazoline to chelate ferric ion. Ferrichrome is an archetypal example of hydroxamate-type siderophore. The third class of siderophore, on top of using N-hydroxy amino side chain together with an oxygen atom, it combines all the three siderophore types and it utilizes three distinctive methods of the binding ferric ion.
The gram-positive bacteria contain outer membrane receptor proteins which exist in their outer membranes (Clark, 15). The outer membrane receptor proteins recognize, bind and then transport the complex (iron-siderophore complex) into the cell periplasm. The outer membrane transport proteins are divided into two, active and passive transporters. Active protein transporters have high binding affinity for ferric ion and ATP provides them with energy (Neilands, 26723). Contrary to active transporters, passive transporters have a low binding affinity for ferric ion and existing chemical gradient supplies them with the energy. The outer membrane receptor proteins consist of two unique domains, the β-barrel, and plug regions. β-Barrel of every protein that inserts across the outer membrane lipid bilayer is generated by twenty-two antiparallel β-strands which are linked to the periplasm by external loops and short turns which extend above the surface of the cell. On the other hand,

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