Nucleic Acids Research, 1985, Vol. 13, No. 11 4143-4153
© 1985
Articles |
Deletion of C-termlnal amino acid codons of PhiX174 gene E: effect on its lysis inducing properties
1Department of Biology, University of Kaiserslautern P.O. Box 3079, D-6750 Kaiserslautern 2European Molecular Biology Laboratory P.O. Box 10.2209, D-6900 Heidelberg 3Department of Genetics and Microbiology, University of Munich Maria Ward Str. la, D-8000 Munich 19, FRG
*To whom correspondence should be addressed, at Department of Genetics and Microbiology, Maria Ward Str. Ia, D-8000 Munich 19, FRG
Received April 1, 1985. Accepted May 16, 1985.
The lysis gene E of bacteriophage PhiX174 has Been subjected to deletion and fusion analysis. Deletions of 11 to 90% of gene E specific nucleotides coding for to C-terminal region of the gene product were cloned under transcriptional control of lambda pL. For this purpose plasmid pSUl was constructed which carries an extended polylinker region downstream of pL. Depending on the number of nucleotides after the last gene E specific codon, various C-terrninal segments of protein E were replaced by 4, 5, 53 or 314 unrelated amino acids. Functional analysis for lysis inducing properties of the various gene E mutants revealed that the final 9 codons of the gene could be deleted without loss of function. However, replacements of 19 or more C-terminal codons eliminated gene E activity. Although the functional site of the gene E product is located within the N-terminal half of the polypeptide, the C-terminal part of the protein appears to exhibit severe influence on conformation and/or regulation of the functional site