Question

Wild‑type E. coli cells can synthesize all 20 common amino acids, but some mutants, called amino acid auxotrophs, are unable to synthesize a specific amino acid and require its addition to the culture medium for optimal growth. Besides their role in protein synthesis, some amino acids are precursors for other nitrogenous cell products, such as the purine and pyrimidine nucleotides. Consider the three amino acid auxotrophs that are unable to synthesize glycine, glutamine, and aspartate, respectively. For each mutant, identify the nucleotide product or products which the cell would fail to synthesize by placing the nucleotide in the bin next to the auxotroph.

Answer 1

Answer:

Complete questions include: Answer Bank: Guanine nucleotides, uridine nucleotides, adenine nucleotides, cytosine nucleotides.

Explanation:

Glycine Auxotroph: Guanine nucleotides and adenine nucleotides (Purine nucleotides)

Glutamine auxotroph: Guanine nucleotides and adenine nucleotides (purine nucleotides)

Aspartate auxotroph: Guanine nucleotides, uridine nucleotides, adenine nucleotides, cytosine nucleotides Both purine and pyrimidine nucleotides)

The amino acids glutamine, glycine, and aspartate provide all the nitrogen atoms of purines in a two ring-closure steps to form the purine nucleus. Pyrimidines are synthesized from carbamoyl phosphate and aspartate.