Uridine nucleotides containing 2, 6-diaminopimelic acid from Escherichia coli.

PARK initially reported z the accumulation of amino acid containing nucleotides in penicillin-treated Staphylococcus aureus. Subsequent work% s has shown that the structure of one of these nucleotides is UDP-GNAc-lactyl-L-Ala-D-Glu-L-Lys-D-Ala-D-Ala. Nucleotides lacking one or more of these amino acids ("incomplete peptides") have also been isolated from this organism. A similar nucleotide containing a,e-diaminopimelic acid in place of lysine was isolated from a DAP-requiring mutant of Escherichia cull 4. This nucleotide has tentatively been assigned the structure UDP-GNAc-lactyl-L-Ala-D-Glu-meso-DAP-D-AlaD-Ala. I t is believed that the peptide is linked to the carboxyl group of the lactic acid. The present communication reports the isolation and partial characterization of four uridine nucleotides from E. cull K235. Two of these nucleotides contain DAP but differ from one another and from the nucleotide described above in the number of alanine residues in the peptide portion of the molecule. The other two nucleotides probably represent "incomplete" nucleotides similar to those reported from Staph. aureus. Nucleotides were extracted from IOO g of acetone-dried E. cull with 3 1 80 % ethanol. After removal of ethanol by evaporation in vacuo, they were chromatographed on Dowex-i resin, chloride form, by batchwise elution with LiC1 as indicated in Fig. ia.