[Analysis of the nucleotide sequence of a small colicinogenic plasmid Cold gene coding for lysis].

The nucleotide sequence of a DNA fragment of a small colicigonenic plasmid Cold-CA23 containing the lysis gene cdl has been defined. An open reading frame has been found within the fragment for 48 amino acid polypeptide with the molecular mass 4920 Da. The polypeptide is homologous to the lysis proteins encoded by the small colicinogenic plasmids ColE1 and CloDF13. The homology was also found for the structural and functional arrangement of the cdl gene and the plasmid CloDF13 lysis gene. The analysis of the possible secondary structures of the lysis protein encoded by cdl gene has revealed the amino acid sequences able to form the alternative structures. The described feature is supposed to be required for lysis protein translocation from cytoplasmatic to outer membrane of Escherichia coli cells.