Table 2.

Substitution sites and bactericidal activities of MBP-pediocin AcH chimeric protein mutants

StrainActivitya of mutantsb with the indicated mutation in the following sequence:
K1 Y Y GN G V TC9 GK H SC14 S V DW G K A T T C24 II N N G AM A WA T GG H Q GNHKC44
N1K5R9E11S14 Y14R18T26T31D34E37 R37K41L42E43 N43W44
L. plantarumNCDO955++c ++++c +++c
P. acidilacticiLB42+++++c +++
L. mesenteroidesLy+++++c +++
E. faecalisM1+++++++++
L. innocuaLin11+++++++++
  • a Activity was tested with 100 μl of IPTG-induced (3 h) culture broths from the substitution mutant strains. The five indicator strains are sensitive to wild-type pediocin AcH and to the wild-type MBP-pediocin AcH chimeric protein. The relative activity levels of mutants retaining activity (indicated by +) are presented in Table 3; inactive mutants are indicated by −.

  • b All mutants are single-amino-acid-substitution mutants.

  • c Both mutants at position 14 and position 37 were inactive. The two mutants at position 43 were partially active. The mutant at position 34 showed a loss of activity against two of the five indicator strains.