Disease relevance of pbp2a

• All six penicillin-binding protein (PBP) genes, namely, pbp1a, pbp1b, pbp2a, pbp2b, pbp2x, and pbp3, of 40 Streptococcus pneumoniae clinical isolates, including penicillin-resistant S. pneumoniae isolates collected in Japan, were completely sequenced [1].
• To facilitate our structural studies of PBPs, we constructed a 5'-truncated version (lacking bp from 1 to 231 encoding the N-terminal part of the protein including the transmembrane domain) of the pbp2a gene of Streptococcus pneumoniae and expressed the truncated gene product as a GST fusion protein in Escherichia coli [2].

High impact information on pbp2a

• The glycosyltransferase domain of penicillin-binding protein 2a from Streptococcus pneumoniae catalyzes the polymerization of murein glycan chains [3].
• These observations suggest that individually the pbp1a, pbp1b, and pbp2a genes are dispensable but that either pbp1a or pbp2a is required for growth in vitro [4].
• All mutants with a disrupted pbp2a gene showed higher sensitivity to moenomycin, an antibiotic known to inhibit PBP-associated glycosyltransferase activity, indicating that PBP2a is the primary target for glycosyltransferase inhibitors in S. pneumoniae [5].
• The pbp2a mutants, but not the other mutants, were more sensitive to moenomycin, a transglycosylase inhibitor [4].
• In the case of the pbp2a gene, up to 13 nucleotide substitutions were observed randomly distributed amongst penicillin-susceptible and resistant isolates, revealing a maximum of five amino acid substitutions in PBP 2A [6].

References