Dictyostelium proteins bearing motifs conserved in penicillin-binding proteins and beta-lactamases

Abstract

The soil-dwelling eukaryotic microorganism Dictyostelium discoideum encodes a protein bearing SNTK, SNN and KTG sequences (DDB0168572) and a protein bearing SISK and HTG sequences (DDB0233562). These sequences are similar to SXXK, S(Y)XN and K(H) T(S)G sequences, which are motifs conserved in penicillin-binding proteins and beta-lactamases. RT-PCR analysis showed that D. discoideum expressed genes for DDB0168572 and DDB0233562 in the growth phase and had decreased expression levels of those genes in the developmental phase. A mutant in which the gene for DDB0168572 was disrupted grew and developed as did the parental strain, indicating that DDB0168572 is dispensable for D. discoideum. Loss of DDB0233562 is thought to be fatal to D. discoideum because no gene-disruption mutant was established.