Synthesis of flagellin and hook subunit protein in flagellar mutants of Escherichia coli K12.

We have examined Escherichia coli K12 flagellar mutants affected in each of 29 different loci for the synthesis of flagellin and hook subunit protein. Immune precipitation experiments were employed by treating cell extracts with antiserum against each protein. Flagellin was synthesized in mutants defective in genes flaS , flaT, flaU and flbC . The flaE and flaZ mutants produced small amounts of flagellin, while all the other mutants failed to produce any detectable amount of flagellin. Hook subunit protein was found in most mutants including those defective in genes flaA , flaB , flaC, flaD , flaE , flaG , flaH , flaL , flaM , flaN , flaO , flaP, flaQ , flaR , flaS , flaT, flaU , flaV , flaW , flaX, flaY , flaZ , flbA , flbC , flbD , and hag but not in mutants of flaK , flaI , and flbB . The results conform to the predictions made by our previous indirect gene fusion study ( Komeda 1982).