Peptide permeases modulate transformation in Streptococcus pneumoniae

摘要: To identify elements participating in the process of transformation, a bank genetically altered mutants Streptococcus pneumoniae with defects exported proteins was assessed for decrease transformation efficiency. One mutant consistently transformed 10-fold less than parent strain. Sequence analysis and reconstitution locus revealed gene, plpA (permease-like protein), which encodes putative substrate-binding protein belonging to family bacterial permeases responsible peptide transport. The derived amino acid sequence this gene 80% similar AmiA, peptide-binding homologue from pneumococcus, 50% over 230 acids Spo0KA is regulatory element sporulation Bacillus subtilis. PlpA fusions alkaline phosphatase (PhoA) were shown be membrane associated labelled [3H]-palmitic acid, probably serves as anchor. Experiments designed define roles ami determinants showed that: (i) > 90% deficient while exhibited up fourfold increase efficiency; (ii) compared parental strain, onset competence an occurred earlier logarithmic growth, whereas delayed mutant; (iii) mutation decreases expression competence-regulated locus. Since permease would fail bind specific ligands, it seems likely that substrate-permease interaction modulates transformation.