Table 3.

Structural parameters of PG from dacmutant sporesa

Genotype% of muramic acid with side chain ofb:% of Dpm in cross-links analyzed by:
Lactaml-AlaTPTriPHPLCFDNB
Wild type 50c 26 ± 123 ± 21.5 ± 0.113 ± 131 (1)
dacA 49 ± 125 ± 425 ± 30.8 ± 0.212 ± 234 (1)
dacB 47 ± 112 ± 143 ± 12.2 ± 0.136 ± 2 (30)d 57 (1)
dacC  51c 26 ± 223 ± 31.4 ± 0.113 ± 331 (1)
dacF 51 ± 128 ± 220 ± 21.4 ± 0.213 ± 130 (2)
dacA dacB 46 ± 111 ± 247 ± 21.0 ± 0.137 ± 3 (28)d 59 (2)
dacA dacC  50c 26 ± 324 ± 30.7 ± 0.114 ± 232 (2)
dacA dacF 50 ± 126 ± 123 ± 20.9 ± 0.113 ± 131 (1)
dacB dacC 46 ± 111 ± 145 ± 22.1 ± 0.236 ± 2 (28)d 59 (2)
dacB dacF e 40 ± 16 ± 457 ± 84.8 ± 0.433 ± 2 (23)d 72 (4)
dacC dacF  51c 30 ± 118 ± 1 1.3c 12 ± 132 (1)
dacA dacB dacC 44 ± 212 ± 254 ± 41.8 ± 0.938 ± 3 (21)d 60 (2)
dacA dacB dacF e 42 ± 29 ± 354 ± 32.5 ± 0.326 ± 5 (15)d 60 (2)
dacA dacC dacF  51c 29 ± 220 ± 20.7 ± 0.113 ± 329 (2)
dacB dacC dacF e 39 ± 29 ± 452 ± 65.4 ± 0.634 ± 2 (27)d 76 (2)
  • a Data are averages of analyses of 3 to 10 independent spore preparations (strain numbers as indicated in Table2) with errors of 1 standard deviation except for cross-linking determinations using FDNB, for which the number of independent determinations is given in parentheses.

  • b Abbreviations: Lactam, muramic-δ-lactam; TP, tetrapeptide; TriP, tripeptide.

  • c These values showed no significant deviation among the samples assayed.

  • d The values in parentheses are for effective cross-links; the remaining cross-links involve a peptide that has been cleaved from the muramic acid by a muramic acid-l-alanine amidase (1, 20, 21).

  • e Values for all dacB dacF strains determined by HPLC analyses were calculated by using only identified peaks and ignoring the elevated baseline. Since the latter area undoubtedly includes a large amount of cross-linked muropeptides, the cross-linking values determined by HPLC are certainly underestimates.