Replacement of all tryptophan residues in T4 bacteriophage lysozyme by tyrosine residues

摘要: Abstract From the structural studies on lysozymes of an amber mutant strain (T4 eM91 ) and a recombinant carrying reversions three different mutations eRRR ), it was found that all these occurred in codon for tryptophan (UGG to UAC) cases revertant strains, residue corresponding mutation changed tyrosine (UAG UAU or UAG); thus, lysozyme from triple recombinant, T4 , residues wild-type were replaced by residues. However, this protein had still 50% enzymic activity also reacted with antibody lysozyme. The mutants derived 126th 158th suppressed suppressors, su + −3, −2 −3 but 138th only . This indicates can be not serine glutamine (in contrast residues), suggesting some specified aromatic moiety at position is necessary activity.