Introduction to Metabolic Pathways

摘要: The major pathway for assimilation of nitrogen is through glutamine. step that links metabolism carbon and conversion 2-ketoglutarate to glutamate It not surprising in gram-negative bacteria the ultimate determinant expression genes ratio intracellular concentrations Some biosynthetic pathways gram-positive have received so little attention they could be subject separate chapters. These include those synthesis L- D-alanine histidine intersecting glycine, serine, cysteine. his Streptomyces coelicolor are organized three unlinked clusters, one which has been sequenced nearly its entirety. route serine biosynthesis Bacillus subtilis Micrococcus luteus 3-phosphoglycerate characteristic most bacteria. first enzyme this pathway, dehydrogenase, feedback inhibited by serine. In Clostridium acidi-urici, however, a different interconversion seems function. case, glycine formaldehyde condense form Mutations at two B. loci cause auxotrophy. SerA- mutants require either or growth. Growth improved if threonine both provided. enzymes sulfate utilization, ATP sulfurylase adenosine-5'-phosphosulfate kinase, activities convert activated sulfite sulfide catalyze incorporation into cysteine present Escherichia coli. only racemization L-alanine.