A cryptic fimbrial gene in Serratia marcescens.
The gene coding for the mannose-sensitive hemagglutinating fimbriae in Serratia marcescens US5 was cloned into Escherichia coli K4 with a cosmid vector system. One of the transformants, US5-1, expressed two morphologically distinct fimbriae, one that was 5-nm wide and one that was 3-nm wide. The latter fimbria was morphologically and serologically indistinguishable from that of strain US5. Genetic analysis of transformant US5-1 showed that the gene responsible for the 5-nm-wide fimbriae was located more than 10 kilobases away from the gene responsible for the 3-nm-wide fimbriae. The molecular sizes of the subunits of these two fimbriae, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, were 19 kilodaltons for the 3-nm-wide fimbriae and 20 kilodaltons for the 5-nm-wide fimbriae. Serologically, the 5-nm-wide fimbriae did not cross-react with monoclonal or polyclonal antibodies raised against the mannose-sensitive hemagglutinating fimbriae of strain US5. Strain EL101, which expressed only the 5-nm-wide fimbriae, did not agglutinate chicken or human erythrocytes. These experimental results suggest that the gene for the 5-nm-wide fimbriae is cryptic in strain US5 and is expressed in E. coli K4 only after it is moved by transformation.
Moriya
T
T
Department of Bacteriology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Kawabata
S
S
Mizunoe
Y
Y
Amako
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D015139:Blotting, Southern; D002645:Chickens; D003001:Cloning, Molecular / Q000379:methods; D003360:Cosmids; D004269:DNA, Bacterial / Q000235:genetics; D004912:Erythrocytes / Q000276:immunology; D004926:Escherichia coli / Q000235:genetics*; D010861:Fimbriae, Bacterial / Q000502:physiology* / Q000648:ultrastructure; D005798:Genes, Bacterial; D005822:Genetic Vectors; D006384:Hemagglutination; D008969:Molecular Sequence Data; D010957:Plasmids; D015183:Restriction Mapping; D012706:Serratia marcescens / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure
D001426:Bacterial Proteins; D004269:DNA, Bacterial