Transport in bacteria

Transport systems can be described in a functional sense according to the number of molecules moved and the direction of movement (Figure 41-10) or according to whether movement is toward or away from equilibrium. A uniport system moves one type of molecule bidirectionally. In cotransport systems, the transfer of one solute depends upon the stoichiometric simultaneous or sequential transfer of another solute. A symport moves these solutes in the same direction. Examples are the proton-sugar transporter in bacteria and the Na+ -sugar transporters (for glucose and certain other sugars) and Na -amino acid transporters in mammalian cells. Antiport systems move two molecules in opposite directions (eg, Na in and Ca out). 

G. Winkelmann, Specificity of iron transport in bacteria and fungi. CKC Haiulhook of Microbial Iron Chelates (G. Winkelmann, ed.) CRC Press, Boca Raton. 1991. pp. 65-106. 

Volume 125. Biomembranes (Part M Transport in Bacteria, Mitochondria, and Chloroplasts General Approaches and Transport Systems)... 

Silver, S. and Walderhaug, M. (1992). Gene regulation of plasmid-determined and chromosome-determined inorganic ion transport in bacteria, Microbiol. Rev., 56, 195-228. 

Vanadium, as V0S04, has been found to interfere with siderophore-mediated iron transport in bacteria and plants. This seems to imply that vanadium can be transported by siderophores, and a number of studies focussing on applications of hydroxamate V-complexes in biology have been initiated. 

The nonprotein amino acid /3-A -methylamino-L-alanine (BMAA) is a neurotoxin found in various species of marine cyanobacteria. This nonprotein amino acid occurs both as a free amino acid and bound to proteins.Siderophores are secondary metabolites generally produced by bacteria under iron-deficient conditions. These molecules sequester and transport ferric ion via active transport in bacteria. Some known siderophores are nonribosomal peptides that contain nonprotein amino acids with terminal amines or hydroxylamine side chains, such as exochelin Many of the known nonprotein amino... 

Winkelmann G (1991) Specificity of Iron Transport in Bacteria and Fungi. In Winkelmann G (ed) CRC Handbook of Microbial Iron Chelates. CRC, Boca Raton, FL, p 65... 

A brief description of sugar transport in bacteria and mammals is given principally to illustrate general principles and to outline the diversity of the processes which have evolved, particularly in mammals. The selection of material for this section is of necessity, therefore, somewhat arbitrary, and more comprehensive surveys of sugar transport may be found in several recent reviews (I, 2, 3, 4, 5, 6, 7, 8, 9,10, II, 12,13, 14). 

Haney, S.A. Oxender, D.L. (1992). Amino acid transport in bacteria. Int. Rev. Cytol. 137A, 37-95. 

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