1. Sources of energy and building blocks in oxidatively stressed D
Sources of energy and building blocks in oxidatively stressed D. radiodurans.
Sources of energy and building blocks in oxidatively stressed D. radiodurans. (A) Extracellular proteolysis. D. radiodurans contains many secreted proteases and ABC transporters, which provide exogenous amino acids as protein building blocks and peptides as components of manganese complexes. (B) The pentose phosphate pathway (PPP) for the conversion of glucose into dNTPs. Glucose is essential for recovery from oxidative stress; glucose-6-phosphate dehydrogenase (the marker enzyme of PPP) converts glucose into the precursors of dNTPs as DNA building blocks and, possibly, components of Mn complexes. (C) Carbohydrate and polyphosphate granules. Shown is a schematic representation of a D. radiodurans tetrad viewed by electron microscopy (based on data from reference 615 and unpublished data from J. R. Battista). The small light granules contain carbohydrates, while the large dark circles represent polyphosphate granules. Both can be used as sources of energy, while polyphosphates also serve as a phosphate source for the synthesis of nucleic acids and, presumably, for manganese-phosphate complexes.
Dea Slade, and Miroslav Radman Microbiol. Mol. Biol. Rev. 2011; doi: /MMBR