FIG. 6.

Differences in structures of PG from outgrowing wild-type spores and spores lacking PBP1 and PBP2a. PG from outgrowing spores was harvested 60 min after the initiation of spore germination and purified, digested, reduced, and separated by HPLC with a 0.1% TFA–20% acetonitrile gradient as described previously (25). The muropeptide profile of a strain lacking both PBP1 and PBP2a (A) is compared to the profile of a strain lacking only PBP1 (B); the latter is identical to that from the wild-type strain (data not shown). The arrows denote peaks whose magnitude is significantly different in the strains lacking PBP1 and PBP1 and -2a. Differences in retention times between the two gradients are the result of slight differences in buffer composition among the different HPLC runs.