Premium
Transport of hemolysin by Escherichia coli
Author(s) -
Härtlein Michael,
Schießl Sigrid,
Wagner Wilma,
Rdest Ursula,
Kreft Jürgen,
Goebel Werner
Publication year - 1983
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.240220203
Subject(s) - gene product , periplasmic space , biology , bacterial outer membrane , escherichia coli , vesicle associated membrane protein 8 , hemolysin , microbiology and biotechnology , biochemistry , cytoplasm , membrane protein , gene , gene expression , membrane , virulence
The hemolytic phenotype in Escherichia coli is determined by four genes. Two (hlyC and hlyA) determine the synthesis of a hemolytically active protein which is transported across the cytoplasmic membrane. The other two genes (hlyB a and hlyB b ) encode two proteins which are located in the outer membrane and seem to form a specific transport system for hemolysin across the outer membrane. The primary product of gene hlyA is a protein (protein A) of 106,000 daltons which is nonhemolytic and which is not transported. No signal peptide can be recognized at its N‐terminus. In the presence of the hlyC gene product (protein C), the 106,000‐dalton protein is processed to the major proteolytic product of 58,000 daltons, which is hemolytically active and is transported across the cytoplasmic membrane. Several other proteolytic fragments of the 106,000‐dalton protein are also generated. During the transport of the 58,000‐dalton fragment (and possible other proteolytic fragments of hlyA gene product), the C protein remains in the cytoplasm. In the absence of hlyB a and hlyB b the entire hemolytic activity (mainly associated with the 58,000‐dalton protein) is located in the periplasm: Studies on the location of hcmolysin in hlyB a and hlyB b mutants suggest that the gene product of hlyB a (protein B a ) binds hemolysin and leads it through the outer membrane whereas the gene product of hlyB b (protein B b ) releases hemolysin from the outer membrane. This transport system is specific for E coli hemoiysin. Other periplasmic enzymes of E coli and heterologous hemolysin (cereolysin) are not transported.