Table 1.

Summary of OmpF mutants with substitutions at the carboxy-terminal phenylalanine residue

Codon 340 substitution for UUCOmpF340 residueOmpF levelaDex phenotypebEOP (K20)c
NonedPhenylalanine1.00+++1.00
UACTyrosine0.96+++0.94
CUCLeucine0.88++0.92
CCCProline0.38++0.64
CACHistidine0.24+++0.70
ACCThreonine0.14+0.65
UCCSerine0.13+0.48
CGCArginine0.08++0.50
GCCAlanine0>10−6
  • a OmpF levels were determined from envelopes of cultures grown overnight without IPTG. Levels relative to that of the parental proteins are shown.

  • b The Dex phenotype was scored on maltodextrin minimal medium after 24 h of incubation at 37°C. Colony sizes of mutants were compared with those of the parental strain.

  • c EOP (K20), efficiency of plaquing for OmpF-specific bacteriophage K20.

  • d Parental codon.