Open AccessStructural analysis and biological significance of the cell wall lytic enzymes of Streptococcus pneumoniae and its bacteriophage
Author(s) -
López Rubens,
García JoséL.,
García Ernesto,
Ronda Concepción,
García Pedro
Publication year - 1992
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1992.tb14074.x
Subject(s) - autolysin , lytic cycle , lysin , bacteriophage , amidase , biology , streptococcus pneumoniae , microbiology and biotechnology , enzyme , bacterial cell structure , biochemistry , bacteria , computational biology , gene , genetics , escherichia coli , virus
Abstract The development of an appropriate technique for the identification of autolysin‐defective mutants of pneumococcus has been a fundamental step to carry out studies on the molecular characteristics of the lytic enzymes of Streptococcus pneumoniae and its bacteriophage. Our results show that the principal pneumococcal autolysin (an amidase) is responsible for the separation of the daughter cells at the end of the cell division. On the other hand, this system provides a reliable experimental model to support the extended idea concerning the modular organization of most proteins. The comparative analyses of the deduced amino acid sequences of these enzymes, as well as the construction of functional chimeric phagebacterial enzymes, demonstrate that the C‐terminal domain, which contains a large number of repeated amino acid motifs, is the substrate‐binding domain, whereas the N‐terminal domain provides enzymatic specificity. We propose that the pneumococcal lytic enzymes have evolved by modular exchange providing examples of the types of novel genes that the bacteria or the phage might create to allow them to become adapted to new environmental situations.