IMMOTILE PHENOTYPE OF AN ESCHERICHIA-COLI MUTANT LACKING THE HISTONE-LIKE PROTEIN HU

The histone-like protein HU in Escherichia coli are encoded by the hup A and hupB genes. A hupA-hupB double deletion mutant has now been show n to express an immotile phenotype. The motility of hupA or hupB singl e mutants was similar to that of wild-type cells. SDS-polyacrylamide g el electrophoresis revealed that the amount of flagellin in the hupA-h upB double deletion mutant was markedly reduced compared with the wild -type strain, suggesting that the immotile phenotype of the double del etion mutant is caused by a loss of flagella.