AUTHOR=Huang Li , Liu Mafeng , Ammanath Aparna Viswanathan , Zhu Dekang , Jia Renyong , Chen Shun , Zhao Xinxin , Yang Qiao , Wu Ying , Zhang Shaqiu , Huang Juan , Ou Xumin , Mao Sai , Gao Qun , Sun Di , Tian Bin , Götz Friedrich , Wang Mingshu , Cheng Anchun 

TITLE=Identification of the Natural Transformation Genes in Riemerella anatipestifer by Random Transposon Mutagenesis

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.712198

DOI=10.3389/fmicb.2021.712198

ISSN=1664-302X

ABSTRACT=<p>In our previous study, it was shown that <italic>Riemerella anatipestifer</italic>, a Gram-negative bacterium, is naturally competent, but the genes involved in the process of natural transformation remain largely unknown. In this study, a random transposon mutant library was constructed using the <italic>R. anatipestifer</italic> ATCC11845 strain to screen for the genes involved in natural transformation. Among the 3000 insertion mutants, nine mutants had completely lost the ability of natural transformation, and 14 mutants showed a significant decrease in natural transformation frequency. We found that the genes <italic>RA0C_RS04920</italic>, <italic>RA0C_RS04915</italic>, <italic>RA0C_RS02645</italic>, <italic>RA0C_RS04895</italic>, <italic>RA0C_RS05130</italic>, <italic>RA0C_RS05105</italic>, <italic>RA0C_RS09020</italic>, and <italic>RA0C_RS04870</italic> are essential for the occurrence of natural transformation in <italic>R. anatipestifer</italic> ATCC11845. In particular, <italic>RA0C_RS04895</italic>, <italic>RA0C_RS05130</italic>, <italic>RA0C_RS05105</italic>, and <italic>RA0C_RS04870</italic> were putatively annotated as ComEC, DprA, ComF, and RecA proteins, respectively, in the NCBI database. However, RA0C_RS02645, RA0C_RS04920, RA0C_RS04915, and RA0C_RS09020 were annotated as proteins with unknown function, with no homology to any well-characterized natural transformation machinery proteins. The homologs of these proteins are mainly distributed in the members of <italic>Flavobacteriaceae</italic>. Taken together, our results suggest that <italic>R. anatipestifer</italic> encodes a unique natural transformation machinery.</p>