Fig. 1

Schematic representation of genotype and phenotype of S. pneumoniae isogenic deletion mutants. Macrolide efflux in Streptococci is associated to the mef(A)–msr(D) macrolide efflux system. The contribution of spr0971, spr1023, spr1932 genes to mef(A) complementation was investigated by constructing isogenic deletion mutants, carrying the recombinant Φ1207.3Δmef(A) phage. Single, double and triple mutants were obtained by PCR gene SOEing and transformation. Genes are reported as arrows, while the cross indicates gene deletions. Spr0971, Spr1023 and Spr1932 proteins are reported as not scaled boxes and the 12 transmembrane domains as bars