DEFINITION OF ADDITIONAL FLAGELLAR GENES IN ESCHERICHIA COLI K12

Abstract

Twentynine flagellar genes in Escherichia coli K12 have previously been assigned to three regions of the genome. Flagellar region I is located between pyrC and ptsG, region I1 between aroD and uvrC, and region I11 between uvrC and his. In this study, flagellar mutants in EscherLchia coli K12 were obtained by selection for resistance to the flagellotropic phage, x. They were analyzed in complementation tests using PI phage-mediated transduction. In addition to the fla genes already described, eight more flagellar genes were identified. This analysis defined six more fla genes in region I (flaU, etc.), one more in region I1 (fZbB) and one more in region I11 (flbC) . Region I was shown to include at least 12 fla cistrons. Complementation analysis with polar Muphage-induced Fla^- mutants and with λfla phage defined four transcriptional units in region I. These were: flaU, flbA-flaw-flav-flaK-flax-flaL-flay-flaM, fluz and flaS-flaT, with transcription proceeding from left to right. The flbB gene was found to be part of an operon: flbB-flal in region 11. In region 111, a previously unidentified gene flbC was located between hag and flaN.