Hemin-Deficient Mutants of Salmonella typhimurium

摘要: Nine hemin-deficient mutants of Salmonella typhimurium LT2 were isolated as neomycin-resistant colonies. Five these could be stimulated by Δ-aminolevulinic acid (Δ-ALA), thus representing hemA mutants. Since S. is not able to incorporate hemin, the identification Δ-ALA was made on basis simultaneous loss catalase activity and cytochromes. The gene mapped conjugation in trp region, probably order purB-pyrD-hemA-trp; episome FT71trp does carry gene. Transductional intercrosses phage P22 indicate that 11, 12, 13, 37 are at very closely linked sites, whereas hemA14 a more distant site same or an adjacent No joint transduction detected between pyrF. loci affected other pro+ marker (frequency linkage, 88 97%), but cotransduction two markers obtained. F lac hem purE, which originates from Escherichia coli K-12, complement LT2. As result, sequence chromosome pro heme analogous found E. K-12. Thus, also possesses regions, with location similar described