%0 Journal Article %A Willetts, N. S. %A Moore, P. M. %A Paranchych, W. %T Variant Pili Produced by Mutants of the Flac Plasmid %D 1980 %J Microbiology, %V 117 %N 2 %P 455-464 %@ 1465-2080 %R https://doi.org/10.1099/00221287-117-2-455 %I Microbiology Society, %X Transfer-proficient Flac mutants with reduced abilities to plate various F-specific phages were isolated, either by selection after mutagenesis, or as revertants of Flac traA mutants. In many of the mutants pilus-related properties were altered, including physical adsorption of R17 phage, the number of pili per cell and the outgrowth/retraction equilibrium. Complementation studies showed that the mutations were in traA, suggesting that specific alterations in the amino-acid sequence of the pilin subunit protein were responsible for the altered pilus properties. Complementation between the Flac traA mutants and the derepressed plasmid R100-1 restored phage sensitivity in some cases, suggesting that the incorporation of both mutant and R100-1 subunits into the pilus structure may result in conformational changes which increase the capacity of the pilus to interact with phages. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-117-2-455